The University of Southampton

Tag: climate change

Help! We’re Sinking: The Drowning Atoll Island Communities

Posted on by Kayra Salih
Figure 1. A typical atoll island, source: http://www.ventanasvoyage.com/images/coral%20atoll.jpg
Figure 1. A typical atoll island, source: http://www.ventanasvoyage.com/images/coral%20atoll.jpg

What is sea level rise (SLR)?

The term is pretty self-explanatory in the sense that sea level is rising globally; it has risen by ~3.1mm yr-1 since the 1990s (Goelzer et al., 2015). This is due to the complex interactions of many drivers under recent climate change (Figure 2). This SLR is having global consequences including the loss of low-lying land, of which atoll islands are of the most vulnerable and threatened (Nicholls et al., 2007).

Figure 2. Diagram illustrating the causes of SLR, source: https://deq.nc.gov/about/divisions/coastal-management/coastal-management-hot-topics/sea-level-rise
Figure 2. Diagram illustrating the causes of SLR, source: https://deq.nc.gov/about/divisions/coastal-management/coastal-management-hot-topics/sea-level-rise

Atoll Island Communities

Atolls are mid-ocean annular reefs surrounding a central lagoon (Figure 1) (Woodroffe, 2008). Atoll islands are notoriously vulnerable to the effects of SLR for three main reasons (see Figure 3 below) (Woodroffe, 2008):

Figure 3. The three main impacts of SLR on atoll islands.
Figure 3. The three main impacts of SLR on atoll islands.

Impacts on Humans

These environmental changes inevitably have impacts on the surrounding ecosystem; affecting the terrestrial, aquatic and marine communities, including human populations. The world is now experiencing a wave of ‘climate change refugees’ (Farbotko & Lazarus, 2012) who have been forced to seek asylum in other countries, for example the islanders of Tuvalu.

Tuvalu is a country in the South Pacific solely consisting of low-lying coral and atoll islands (Figure 4) (Farbotko & Lazrus, 2012). Residents have already been forced to evacuate their homes due to flooding, in addition to saltwater incursion rendering their groundwater drinking source unsuitable (Connell, 2016). Sea level around Tuvalu is currently rising by ~5.1mm yr-1 (Connell, 2016). This is a common tale throughout Earth’s atoll islands, and one which is likely to become more common in the future.

Figure 4. Map of Tuvalu showing its many atoll islands, source: http://www.nanumea.net/Photos%20page/Tuvalu%20Map%20with%20arrow%20and%20ack%20-%20from%20Smithsonian%20(a).jpg
Figure 4. Map of Tuvalu showing its many atoll islands, source: http://www.nanumea.net/Photos%20page/Tuvalu%20Map%20with%20arrow%20and%20ack%20-%20from %20Smithsonian%20(a).jpg

Effects on Marine Organisms

The marine ecosystem surrounding islands is also experiencing adverse and damaging impacts from sea level rise. For example, the health of coral reefs is already being degraded by warming oceans contributing to coral bleaching (Figure 5).

Figure 5. Infographic explaining coral bleaching and its causes, source: http://oceanservice.noaa.gov/facts/coralbleaching-large.jpg
Figure 5. Infographic explaining coral bleaching and its causes, source: http://oceanservice.noaa.gov/facts/coralbleaching-large.jpg

It can be argued that rising sea levels may in fact protect corals from overexposure to sunlight as they are deeper (Woodroffe & Webster, 2014). However, this will mostly mean that corals are too deep to allow their symbiotic algae to survive, which will ultimately lead to coral death (Woodroffe & Webster, 2014).

These impacts lead to wider community impacts on marine organisms; coral-dependent fish will either migrate or die (Andréfouët et al., 2015). The decline in fish stocks will also affect human populations which depend on this resource. Furthermore, the whole community will be affected by changes in food resources and suitable habitat, possibly leading to the collapse of the ecosystem (Andréfouët at al., 2015).

The future…

More areas are predicted to be underwater in the future according to SLR projections (Goelzer et al., 2015). This will not only have an impact on the animal populations dependent on fragile atoll ecosystems; but also on human populations- with an increasing number of environmental asylum seekers. The future will likely see increasing numbers of atoll island communities drowning!

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References

Andréfouët, S., Dutheil, C., Menkes, C.E., Bador, M. & Lengaigne, M. (2015). Mass mortality events in atoll lagoons: environmental control and increased future vulnerability. Global Change Biology. 21:195-205.

Connell, J. (2016). Last days in the Carteret Islands? Climate change, livelihoods and migration on coral atolls. Asia Pacific Viewpoint. 57:3-15.

Farbotko, C. & Lazrus, H. (2012). The first climate refugees? Contesting global narratives of climate change in Tuvalu. Global Environmental Change. 22:382-390.

Goelzer, H., Huybrechts, P., Loutre, M.F. & Fichefet, T. (2015). Future rates of sea-level rise from long-term coupled climate-ice sheet projections. In: EGU General Assembly Conference Abstracts. 17:15590.

Nicholls, R.J., Wong, P.P., Burkett, V.R., Codignotto, J.O., Hay, J.E., McLean, R.F., Ragoonaden, S. & Woodroffe, C.D. (2007). Coastal systems and low-lying areas. In: Parry, M.L., Canziani, O.F., Palutikof, J.P., van der Linden, P.J. & Hanson, C.E. (Eds.). Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press: UK. pp. 315-356.

Woodroffe, C.D. (2008). Reef-island topography and the vulnerability of atolls to sea-level rise. Global and Planetary Change. 62:77-96.

Woodroffe, C.D. & Webster, J.M. (2014). Coral reefs and sea-level change. Marine Geology. 352:248-267.



Climate Change IS happening, and it’s set to starve the planet… (The opposite of FAKE NEWS!)

Posted on by Anonymous

With the large scale funding cuts of the Environmental Protection Agency in the USA, the current rapid rates of climate change and CO2 release show no hope of stopping.

But seeing as though plants breathe using CO2 (through the process of photosynthesis), and use carbon in their growth, surely the increased amounts of CO2 being pumped into our atmosphere is a good thing for plants?  As studies have shown; perhaps not…

Plants require very specific environmental conditions to function efficiently, and any changes in these conditions can be detrimental.  Although it has been shown that increased CO2 initially causes an increase in the rate of photosynthesis and growth of leaves and roots (Taylor et al 1994), generally, in the long-term, the stimulation of photosynthesis is actually suppressed!

This is mainly due to negative effects on the plants function, such as the build-up of excess starch (sugars) in leaves via increased photosynthesis, hindering breathing of CO2 via pores; called the stomata (Makino & Mae 1999), and increased CO2 also causes the stomata to partially close (Singh 2009), resulting in an inability to respire efficiently (Ryan 1991).

The mechanism for respiration in a plant leaf, through the stomata.
The mechanism for gas exchange in a plant leaf, through the stomata.  Source: Understanding Evolution

The failure to respire efficiently can cause the death of many food crops globally that are vital to feeding our populations!

Increased environmental CO2 also results in global warming due to increased reflection of the Sun’s radiation back to the Earth’s surface; and a temperature increase of 2-3⁰C over the next 30-50 years (IPCC 2007) is predicted to cause problems for our crops.  For example, warmer temperatures affect plants mainly when they are developing, and this has been shown to reduce the numbers of our food crop plants by 80%-90% (Hatfield & Prueger 2015), having dire consequences for our food supplies!

The global change in surface temperature from 1901-2012. A worrying trend that is set to worsen... Source: National Snow & Ice Data Center
The global change in surface temperature from 1901-2012. A worrying trend that is set to worsen… Source: National Snow & Ice Data Center

Climate change is also set to increase the frequency of extreme weather events (Rosenzweig et al 2001). With increased storms and flooding drowning plants in some areas, and in other areas increased drought, resulting in a lack of water for plants to function with, which they rely heavily on for processes such as photosynthesis, vital for growth and survival.  The equation for photosynthesis is shown below, in case you have forgotten…

 

The equation for photosynthesis, showing how carbon dioxide and water are transformed into oxygen and sugars through the light energy from the sun hitting the chlorophyll pigments in the plants cells.
The equation for photosynthesis, showing how carbon dioxide and water are transformed into oxygen and sugars through the light energy from the sun interacting with the chlorophyll pigments in the plants cells.

 

With increasing global temperatures, drought affected areas will increase from 15.4% to 44.0% by 2100 (Li et al 2009) – resulting in less land to grow crops, which will be disastrous for our food security, along with the fact that the number of suitable growing days per year for our crops will decrease by 11% by the year 2100 (Mora et al 2015)!

A sunny day on a Californian beach? Not exactly… This is Californian farmland suffering from a severe drought – completely unusable!
A sunny day on a Californian beach? Not exactly… This is Californian farmland suffering from a severe drought – completely unusable! Source:  New York Times

 

With the saying “Feed the World” becoming more and more poignant, our future looks bleak, as we are set to have less food security per person than ever before due to the detrimental effects that climate change will have on plant function. Also, plants not only provide food, but are also at the heart of our medicines and resources! So maybe Donald Trump ought to reconsider his views on climate change before threatening his new healthcare system before it has begun.

Word Count: 500

 

References:

Hatfield, J. and Prueger, J. (2015). Temperature extremes: Effect on plant growth and development. Weather and Climate Extremes, 10, pp.4-10.

IPCC, (2007). Climate Change 2007: Impacts, Adaptation and Vulnerability. New York: Cambridge University Press, p.17.

Li, Y., Ye, W., Wang, M. and Yan, X. (2009). Climate change and drought: a risk assessment of crop-yield impacts. Climate Research, 39, pp.31-46.

Makino, A. and Mae, T. (1999). Photosynthesis and Plant Growth at Elevated Levels of CO2. Plant and Cell Physiology, 40(10), pp.999-1006.

Mora, C., Caldwell, I., Caldwell, J., Fisher, M., Genco, B. and Running, S. (2015). Suitable Days for Plant Growth Disappear under Projected Climate Change: Potential Human and Biotic Vulnerability. PLOS Biology, 13(6), p.e1002167.

Rosenzweig, C., Iglesius, A., Yang, X., Epstein, P. and Chivian, E. (2001). Climate change and extreme weather events – Implications for food production, plant diseases, and pests. Global Change & Human Health, 2(2), pp.90-104.

Ryan, M. (1991). Effects of Climate Change on Plant Respiration. Ecological Applications, 1(2), pp.157-167.

Singh, S. (2009). Climate change and crops. 1st ed. Berlin: Springer, pp.5-6.

Taylor, G., Ranasinghe, S., Bosac, C., Gardner, S.D.L. and Ferris, R. (1994). Elevated CO2 and plant growth: cellular mechanisms and responses of whole plants. Journal of Experimental Botany, 45, pp.1761-1774.



Honey, I can’t bee-lieve what I’m seeing!

Posted on by Luke Donovan
Why does it keep getting hotter ... and where has my home gone?!
Why does it keep getting hotter … and where has my home gone?!

Enjoying that tangerine? That glass of cranberry juice this morning? Waking up in those 100% cotton bed sheets? Well, you can thank the bees. They are the major pollinators of plants and crops in ecosystems and are invaluable to us (Brown and Paxton, 2009; Costanza et al., 1997). Unfortunately, bees are declining, mainly through human causes (boo!). Habitat loss, fragmentation, invasive species and climate change are all factors that are harming the bee populations.

Homes under the hammer – no, not the TV show

The human population is set to reach ~9 billion by 2050 (United Nations, 2004), seeing an increase in resources to feed all these mouths. Habitats need to be converted into farmland to provide crops (which ironically will be pollinated by bees!). It is known that human disturbance can negatively impact bee numbers (Winfree et al., 2009). It could also cause populations to inbreed, meaning they are susceptible to nasty diseases causing death (Brown and Paxton, 2009). The more we harm bee habitats, we are causing detriment to their numbers and are also causing a negative effect on our lives – how counterproductive.

More food and less destruction! (pintrest.com)
More food and less destruction!

How did you get here?!

Sometimes you get an unfamiliar, ugly head pop up in a population which is causing harm to the original species that live there – otherwise known as an invasive species. The process is usually:

  • Introduction
  • Colonisation
  • Naturalisation
  • Spread
  • Impact

 

This can be seen in the Africanized honeybee in South America, largely replacing the European honeybee by outcompeting it (Schweiger et al., 2009).

Left: Africanized Honey bee - Right: European Honey Bee
Left: Africanized Honey bee – Right: European Honey Bee.

Nature has no air-conditioning: Get used to the warm!

Despite belief from certain world leaders, climate change is happening. Climate change brings many problems to bee populations, such as a change in the relationship between plants and the bees and an increase in disease and parasites (Le Conte and Navajas, 2008).

In snowy environments, climate change is causing snow to melt earlier, meaning flowers are emerging earlier, causing bees to be out of sync (phenology), thus causing changes in what’s called their ‘functional traits’ which are traits that typically relate to changes in the environment.

Bees must build up sufficient honey stores so that they can survive over the winter periods, however climate change is causing a change in flower development (and pollen production) whereby drought is responsible for the decline in flower numbers (La Conte and Navajas, 2008). This means that the bees cannot build the right amount of honey stores and starve over the winter period.

The future of the bees

There are conservation efforts to try and help bees (woo!) such as (Brown and Paxton, 2009):

  • Minimising habitat loss
  • Making agricultural habitats bee-friendly
  • Training scientists and the public

 

If bees were to go extinct tomorrow, we would have to self-pollinate EVERYTHING, as bees do all this hard work for us, for nothing. If we lose bees, we lose the planet, we must ensure bees do not leave us otherwise the future will look very bleak (with no hint of yellow and black).

Thanks for reading, lets hope we see these guys buzzing around for a long time
Thanks for reading, lets hope we see these guys buzzing around for a long time.

[498 words]

References

Brown, M. and Paxton, R. (2009). The conservation of bees: a global perspective. Apidologie, 40(3), pp.410-416.

Costanza, R., d’Arge, R., de Groot, R., Farber, S., Grasso, M., Hannon, B., Limburg, K., Naeem, S., O’Neill, R., Paruelo, J., Raskin, R., Sutton, P. and van den Belt, M. (1997). The value of the world’s ecosystem services and natural capital. Nature, 387, pp.253-260.

Le Conte, Y. and Navajas, M. (2008). Climate change: impact on honey bee populations and diseases. Rev. sci. tech. Of. int. Epiz, 27(2), pp.499-510.

Schweiger, O., Biesmeijer, J., Bommarco, R., Hickler, T., Hulme, P., Klotz, S., Kühn, I., Moora, M., Nielsen, A., Ohlemüller, R., Petanidou, T., Potts, S., Pyšek, P., Stout, J., Sykes, M., Tscheulin, T., Vilà, M., Walther, G., Westphal, C., Winter, M., Zobel, M. and Settele, J. (2010). Multiple stressors on biotic interactions: how climate change and alien species interact to affect pollination. Biological Reviews, 85, pp.777-795.

United Nations (2004) World Population to 2300, New York. [online] http://www.un.org/esa/population/ publications/longrange2/WorldPop2300final.pdf

Winfree, R., Aguilar, R., Vázquez, D., LeBuhn, G. and Aizen, M. (2009). A meta-analysis of bees’ responses to anthropogenic disturbance. Ecology, 90(8), pp.2068-2076.



The Great Barrier Reef – Not so Great Anymore

Posted on by Edward Simmons

The great barrier reef is a place that the vast majority of people have heard of, perhaps due to its incredible natural beauty, or maybe due

Figure 1: An image of the great barrier reef we’re all familiar with; full of colour and life. Source: Cruiseexperts.com
Figure 1: An image of the great barrier reef we’re all familiar with; full of colour and life.
Source: Cruiseexperts.com

to the large host of species that it supports. Around 150 soft corals, 411 hard corals, 1625 bony fish, and about 1300 crustacean species call the great barrier reef their home, to name a few (Great barrier reef marine park authority, 2014). However, climate change is impacting the corals that make up the structure of the reef, with an estimated yearly loss of around 3,168km2 per year being the calculated loss between 1997 and 2003 alone (Bruno and Selig, 2007).

 

 

 

 

What are the Impacts of Climate Change?

 

Figure 2: Sea surface temperature anomalies for the Coral Sea, 1900-2013, using 1961-1990 average as a baseline. Source: Great barrier reef marine park authority, 2014
Figure 2: Sea surface temperature anomalies for the Coral Sea, 1900-2013, using 1961-1990 average as a baseline. Source: Great barrier reef marine park authority, 2014

Climate change has caused the sea surface temperatures to rise in recent years, as shown by figure 2 for the Coral Sea. In fact, the past 15 years has shown the hottest temperature averages all together, and this has many impacts on the animals and plants that live within the sea. This temperature rise leads to a phenomenon called coral bleaching. This is where corals lose their symbiotic algae, which live within the coral and provide it energy, which can lead to the coral’s death if the bleaching is prolonged or severe. The effects of this are easily seen, as the corals lose their colour, leaving just the white of the calcium skeleton (Brown, 1997).

As the temperature of the water increases, so does its ability to absorb CO2, leading to ocean acidification. The current level of atmospheric CO2 has been measured at 406.42 ppm, (NOAA, 2017), which is more than 100ppm above the maximum values seen over the last 740,000 years (Hoegh-Guldberg et al. 2007). 25% of the CO2 created by humans goes into the sea, leading to significant acidification. As the water turns more acidic, corals are unable to create their calcium skeletons as well, decreasing the rate at which they grow. The growth of corals has in fact decreased by 13.3% since 1990 (De’ath et al. 2009).

Climate change may lead to indirect damages to coral reefs too, with it leading to an increase in both the number and the intensity of storms, including hurricanes, in some regions (Hughes et al. 2003). This damages the corals, and the increase in frequency of the storms gives the reef less time to recover, killing some corals completely.

 

 

 

More than just the corals

Figure 3: Drained of colour, a contrast between a reef before and after bleaching. Source: dw.com
Figure 3: Drained of colour, a contrast between a reef before and after bleaching. Source: dw.com

The health of the corals also effect the many animals that inhabit the reef. The worst affected are the fish that require live corals as their homes, but fish that don’t depend on live coral are impacted too, as they are still dependent on the complexity of structure that the live coral bring (Pratchett et al. 2008).

With climate change growing more intense year by year, up to 60% reefs may be lost by 2030, and with them all the life which calls the reef home (Hughes et al, 2003).  So, while it certainly remains a barrier reef, perhaps it’s not so great anymore…

 

 

[Words: 500]

 

References

 

  • Brown B.E. 1997. ‘Coral bleaching: causes and consequences’ Coral reefs, 16, pp. 129-138
  • Bruno J.F. and Selig E.R. 2007. ‘Regional Decline of Coral Cover in the Indo-Pacific: Timing, Extent, and Subregional Comparisons’ PLoS one 2(8), e711
  • De’ath G., Lough J.M., Fabricus K.E. 2009. ‘Declining Coral Calcification on the Great Barrier Reef’ Science, 323, pp. 116-119
  • Great Barrier Reef Marine Park Authority 2014, Great Barrier Reef Outlook Report 2014, GBRMPA, Townsville.
  • Hoegh-Guldberg O. et al. 2007. ‘Coral Reefs Under Rapid Climate Change and Ocean Acidification’ Science, 318, pp. 1737-1742
  • Hughes T.P. et al. 2003. ‘Climate Change, Human Impacts, and the Resilience of Coral Reefs’ Science, 301, pp. 929-933
  • National Oceanic and Atmospheric Administration (NOAA), 2017. Trends in Atmospheric Carbon Dioxide. [Online] Available at: https://www.esrl.noaa.gov/gmd/ccgg/trends/index.html [Accessed: 21/03/2017]
  • Pratchett M.S. et al. 2008. ‘Effects of climate-induced coral bleaching on coral-reed fishes – ecological and economic consequences. Oceanography and marine biology: an annual review, 46, pp. 251-296


Crops and Climate Change: the good, the bad and the ugly truth

Posted on by Anonymous

New Year, New Hope? But 2017 began with Britain being hit with a vegetable shortage!

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(Independent, 2017)                                                    (The Guardian, 2017)

But apart from halting our “clean eating” resolutions…..

Is a courgette shortage really the end of the world?

Well, probably not! But globally, food security is no laughing matter.

 And what is the cause you may ask? Climate change, of course!

The evidence for climate change is overwhelming.

The Earth’s average temperature has increased by 0.85°C between 1980-2012 (IPCC, 2014). This may seem insignificant, yet, it has severe consequences, such as the ice caps melting, sea levels rising and increased occurrence of extreme weather events (Overpeck and Cole, 2006).

3

Globally averaged combined land and ocean surface temperature (IPCC, 2014)

Humans are to blame.

Since the industrial revolution, burning of fossil fuels has increased emissions of carbon dioxide (CO2) and other greenhouse gases (GHGs) These GHGs act as a blanket, trapping energy in the atmosphere, causing Earth’s temperature to rise (IPCC, 2014).

4

Global Human CO2 Emissions, IPCC, 2014

The good?

Higher CO2 levels increase plant photosynthesis (Pospisilova and Catsky, 1999). Photosynthesis depends on an enzyme called Rubisco, which evolved at higher prehistoric CO2 levels, therefore has higher activity when CO2 increases (Bowes, 1996). This increases plant growth, thereby increasing crop yield, in a phenomenon termed “CO2-fertlisation” (Allen, 1990).

This is particularly pronounced plants categorised at C3 , which includes major crops such as rice, wheat and soybean. Increasing CO2 to 550pm causes 10-20% increase in C3 crop yield, but only 0-10% increase plants categorised as C4, which includes the crops maize and sorghum (Schmidhuber and Tubiello, 2007).

CO2 enters plants through stomata (plant pores), therefore, at higher CO2 levels the stomata need not open as often, termed reduced stomatal conductance. This decreases the amount of water lost through the pores in the process of transpiration, thereby increasing the water efficiency of the plants (Drake et al., 2007).

The bad?

So, is climate change good for plants if it causes increased growth and higher water efficiency? Well no, it was never going to be that simple…

Extreme weather events negatively impact food security, both directly by reduced yields from damaged crops but also indirectly by increasing the chance of landslides and soil erosion, thereby reducing the land available for agriculture (Cerri et al., 2007).

This issue is becoming more urgent as global population increases at an unprecedented rate, increasing the demand for food (MA, 2005).

Food security issues are not only concerned with the quantity of food but also the quality, as globally many people suffer from malnutrition (MA, 2005). Elevated CO2 decreases the zinc, iron, and protein content in wheat, barley, and rice (Myers et al., 2014).

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The two-fold effect of increased CO2 form increased carbon emissions; most likely the negative effect will outweigh the positive effect. 

The ugly truth

Unfortunately, it is predicted the losses will outweigh any gains from CO2 fertilisation.

Ultimately, lack of food could see increased prices for consumers in the developed world whilst the developing world will suffer with food shortage and malnutrition.

Lack of courgettes may seem a trivial matter but is it just one more sign that we getting closer to the tipping point of our planet’s ability to cope with climate change.

Word count: 499

References

Allen, L.H. Jr. (1990). Plant responses to rising carbon dioxide and potential interactions with air pollutants. J. Environ. Qual, 19: 15-34.

Bowes G. (1996) Photosynthetic responses to changing atmospheric carbon dioxide. pp. 387-407. In: N.R. Baker (ed.). Photosynthesis and the Environment. Advances in Photosynthesis, Vol. 5, Kluwer, Dordrecht

Cerri, C. E.P., Sparovek, G., Bernoux, M., Easterling, W.E., Melillo, J. M., and Cerri C. C. (2007). Tropical Agriculture and Global Warming: Impacts and Mitigation Options. Sci. Agric., 64(1): 83-89.

Drake, B.G., Gonzàlez-Meler, M.A. and Long, S.P., 1997. More efficient plants: a consequence of rising atmospheric CO2? Annual review of plant biology, 48(1): 609-639.

IPCC. (2014) Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. R.K. Pachauri and L.A. Meyer (eds.). IPCC, Geneva, Switzerland, pp. 151.

Millennium Ecosystem Assessment (2005). Ecosystems and Human Well-being: Synthesis. Island Press, Washington, DC.

Myers SS, Zanobetti A, Kloog I, et al. (2014). Rising CO2 threatens human nutrition. Nature. 510(7503): 139-142.

Overpeck, J.T. and Cole, J.E. (2006). Abrupt change in Earth’s climate system. Annual Review of Environment and Resources, 31: 1-31.

Pospisilova, J. and Catsky, J. (1999). Development of water stress under increased atmospheric CO2 concentration. Biologia Plantarum, 42: 1-24.

Schmidhuber, J. and Tubiello, F.N. (2007). Global food security under climate change. Proc. Natl. Acad. Sci. USA, 104(50): 19703-8.



How do you like your toast in the morning? Without the worry of food security?

Posted on by Imogen Vieten

80% of human calorie intake comes from 6 major crops including – maize, wheat and rice1. For all people, at all times to have physical and economic access to sufficient food needed for a balanced diet2–food security, the production and distribution of these crops is vital.

Present day representation of global vulnerability to food insecurity8. Explore scenarios of Greenhouse gas emissions and adaptation to climate change impacts on food security by clicking on the link: http://www.metoffice.gov.uk/food-insecurity-index/ Present day representation of global vulnerability to food insecurity3. Explore scenarios of Greenhouse gas emissions and adaptation to climate change impacts on food security by clicking on the image.

A growing human population increases pressure to enhance crop production. 1 billion ha of land will be converted by 2050 for agriculture, reducing absorption of atmospheric carbon dioxide by plants2 and restoration of gaseous balance in the atmosphere, with fewer plants to act as a CO2 ‘sink’.

Human induced climate change is negatively affecting ecosystems, crop yield and production. Since the industrial revolution greenhouse gas emissions have risen, with atmospheric CO2 levels currently at 406.42ppm4, meaning plants are growing in conditions not experienced for 26 million years5.

Impacts of future climate change are predicted to be severe, varying between regions, through changes in temperature, precipitation and increases in extreme weather events. Methods of crop production such as sustainable intensification are needed to increase yields and overcome threats to livelihoods and food security2.

Will increased CO2 result in higher crop yields?

During photosynthesis plants use CO2, water and light to produce oxygen and carbohydrates for growth. Efficiency of this depends on the enzyme Rubisco, which functions better in high CO2, shown experimentally to increase photosynthesis by 58%5. There is evidence that the number and size of individual cells increase in elevated CO26, showing species specific adaptive ability7,  indicating potential to increase crop yield. However other climatic stresses will have negative effects.

The temperature dependant action of Rubisco may become less efficient with rising global temperatures. Furthermore in the long term, plants can acclimatise as additional carbohydrates produced from photosynthesis cannot be used5.

During extended periods of high CO2 exposure the number of stomata- pores used in gaseous exchange in leaves, may decrease indicating that photosynthetic rate will too7.

How will crop production be affected?

For sustainable intensification sufficient water and nutrients8 are required, which will be threatened by increased extreme weather events- from drought affecting water supply to storms where heavy downpours can wash away top soil, reducing land fertility.

Threats to global productivity and changes in yield could have impacts worldwide8. If production decreases, prices of grain products and meat reliant on grain as a feedstock will increase8. Furthermore lower agricultural output, especially in the developing world, leads to lower incomes, with the poorest suffering the most.

High CO2 can decrease food quality with a decline in protein, nitrogen, zinc and iron concentrations in crops9, potentially causing adverse health effects, and necessitating consumption of greater quantities.

Securing the future

FACE (Free-air concentration enrichment) experiments expose crops to elevated CO2 to examine responses and adaptions of ecosystems. Research to develop climate resilient crop varieties to better cope with heat, drought and salinity is also being conducted.

By adapting farming mechanisms and increasing yield and tolerance of essential crop species to environmental extremes, can we ensure food security? Yes, the time to act is now!

 

Discover more about how farmers may adapt their practices to a changing climate in the video ‘Feeding Nine Billion’10

 

[499 Words]

References

  1. Campell, N,A., Reece, J, B., Urry, L,A., Cain, M,L., Wasserman, S, A., Minorsky, P, V., Jackson, R, B. (2015). Seed Plants. In: Wilbur, BBiology A Global Approach. 10th ed. Essex: Pearson. p707.
  2. Sunderland, T., Powell, B., Ickowitz, A., Foli, S., Pinedo-Vasquez, M., Nasi, R. and Padoch, C. (2013). Food security and nutrition: The role of forests. Center for International Forestry Research. Discussion Paper, p1-20.
  3. Met Office. (2017).Food Insecurity Climate Change. Available: http://www.metoffice.gov.uk/food-insecurity-index/. Last accessed 18th March 2017.
  4. CO2 (2017). Earth’s CO2 home page. Available: https://www.CO2.earth/earths-CO2-main-page. Last accessed 20th March 2017.
  5. Drake, B, G. and Gonzàlez-Meler, M, A. (1997). More Efficient Plants: A Consequence of Rising Atmospheric CO2?.Annual Review of Plant Physiology and Plant Molecular Biology. 48, p609-639.
  6. Taylor, G., Ranasinghe, S., Bosac, C., Gardner, S and Ferris, R. (1994). Elevated CO2 and plant growth: cellular mechanisms and responses of whole plants. Journal of Experimental Botany. 45 (Special Issue). P 1761-1774
  7. Long, S, P., Ainsworth, E, A., Rogers, A. and Ort, D, R. (2004). Rising Atmospheric Carbon Dioxide: Plants FACE the Future.Annual Review of Plant Biology. 55, p591-628.
  8. Nelson, G, C., Rosegrant, M, W., Koo, J., Robertson, R., Sulser, T., Zhu, T., Ringler, C., Msangi, S., Palazzo, A., Batka, M., Magalhaes, M., Valmonte-Santos, R., Ewing, M. and Lee, D. (2009). Climate Change: Impact on Agriculture and Costs of Adaptation.International Food Policy Research Institute. Available at: http://www.fao.org/fileadmin/user_upload/rome2007/docs/Impact_on_Agriculture_and_Costs_of_Adaptation.pdf. Last accessed 19th March 2017
  9. Myers, S., Zanobetti, A., Kloog, I., Huybers, P., Leakry, A., Bloom, A., Carlisle, E., Dietterich, L., Fitzgerald, G., Hasegawa, T., Holbrook, N., Nelson, R., Ottman, M., Raboy, V., Sakai, H., Sartor, K., Schwartz, J., Seneweera, S., Tausz, M. and Usui, Y. (2014). Increasing CO2 threatens human nutrition. Nature, 510, p139-142
  10. Fraser, E. (2014). Feeding Nine Billion Video 6: Climate Change and Food Security. Available: https://www.youtube.com/watch?v=cYq2elstFWQ. Last accessed 18th March 2017.


From Sex to Starvation: Impacts of Decreasing Sea Ice on Arctic Communities

Posted on by James McWhirter

When you hear the word climate change, your mind immediately envisions a lonely polar bear swimming through a vast ocean looking for some lost ice on which to rest. If only it could be said that this was simply a dramatisation envisioned by climate change extremists in order to scare us into reducing our greenhouse emissions. If only…

Despite their constant denial, Fox News' can't say global warming isn't affecting their viewer ratings... (Mike Luckovich, 2015)
Despite their constant denial, Fox News’ can’t say global warming isn’t affecting their viewer ratings… (Image: Mike Luckovich, 2015)

Since the 1970’s, Arctic sea ice has decreased at a rate of 13.3% per decade, translating to loss of 13,500 square miles of sea ice coverage annually (Comiso et al., 2008). This drastic loss in sea ice coverage is having severely negative impacts on arctic animals that rely upon it for survival.

Sea ice extent (1970 - 2007) and projected decrease (2030 - 2100). (NOAA GFDL Model, n.d.)
Sea ice extent (1970 – 2007) and projected decrease (2030 – 2100). (Image: NOAA GFDL Model, n.d.)

Polar Bears:

Sea ice loss can be regarded as the main driver responsible for the 22% decrease in polar populations since 1987 (Derocher, 2004). Not only is the sea ice that is so necessary for them to hunt on disappearing, but their penile bones are fracturing during their most intimate moments.

While the function of a penis bone is still unknown (Simmons and Firman, 2013), many animals have them and it seems that chemical pollutants called PCBs may be having detrimental effects on the genitalia of polar bears.  It is suggested that PCBs cause (Sonne et al., 2006; Sonne et al., 2015):

  • Smaller testes
  • Smaller penis bones
  • Lower calcium density in penis bones making them weaker

 

The loss of sea ice has accelerated the incidence of penile fracture as lowered foraging ability has led to skinnier bears, and therefore higher levels of circulating pollutants due to nutritional stress (Sonne et al., 2015).

Reduced reproductive success will have a severe impact on future populations.

“If it breaks, you probably won’t have a bear that can copulate” – Christian Sonne, 2015

PCBeware!! (Image: Paul Nicklen/NGS)
PCBeware!! (Image: Paul Nicklen/NGS)

Walruses:

Walruses are being forced to utilise sea ice in areas of greater depth where there is no food, or move onto solid land (Greenpeace, 2012). Thousands of deaths in beaching populations have been reported due to overcrowding and panic stampedes into the water (Chadwick and Fischbaik, 2008), which are particularly dangerous to young pups. A number of abandoned calves have been observed swimming in water with depths of 3000m, as mothers are forced to deeper waters due to lack of food at overcroweded beaches (Cooper et al, 2006).

Retreating sea ice is driving thousands of Walruses towards land causing major overcrowding. There are an estimated 35,000 walruses on this beach (Photo: Corey Arrardo / NOAA/NMFS/AFSC/NMML)
Retreating sea ice is driving thousands of Walruses towards land causing major overcrowding. There are an estimated 35,000 walruses on this beach (Photo: Corey Arrardo / NOAA/NMFS/AFSC/NMML)

Ice Seals:

Ice seals require sea ice for birthing, pup rearing and resting. As ice is melting earlier in the year, pups are unable to complete their 6 week nursing period due to the premature collapse of shelters, exposing them to the elements and predators (Greenpeace, 2012). In 2002, 75% of Harp seal pups died due to lack of ice (Carillo-Rubio, 2011).

Pup counts and the total number of Northern Fur Seal between 1978 and 2008. The decrease in total pup counts (000's) is notable. (COSEWIC Assessment and Status Report on the Northern Fur Seal in Canada, 2010)
Pup counts and the total number of Northern Fur Seal between 1978 and 2008 on St. Paul I island. The decrease in total pup counts (000’s) is notable. (COSEWIC Assessment and Status Report on the Northern Fur Seal in Canada, 2010)

Bowhead Whales:

Ice-free waters will potentially impact permanent marine mammals. Bowhead whales calve under sea ice as it provides a safe environment from Killer whales, their primary predators (Moore and Laidre, 2006). The future lack of sea ice is likely to increase predation on whale calves, decreasing the reproductive success of the species and decreasing global population. Increased exposure to the sun may also be detrimental as these whales are heat intolerant, and don’t have an ability to combat this.

Bowhead Whales calve under the protection of the sea ice. (Image: Department of Fisheries and Oceans Canada)
Bowhead Whales calve under the protection of the sea ice. (Image: Department of Fisheries and Oceans Canada)

This brief overview of some of the largest and most prevalent Arctic organisms provides a good indication of the fragility of the community assemblage present in this ecosystem.

Artists impression of the Arctic ecosystem and ultimately the organisms at risk from climate change (Image: Oceans North, The Pew Charitable Trust)
Artists impression of the Arctic ecosystem and ultimately the organisms at risk from climate change (Image: Oceans North, The Pew Charitable Trust)

References:

Carillo-Rubio L (2011). Seals and their race against climate change. Climate Institute. www.climate.org/topics/ecosystems/seals-battle-climatechange.html [Accessed: 22/03/17]

Chadwick VJ & Fischbach AS (2008). US Geological Survey Factsheet 2008-3041. Pacific Walrus response to Arctic sea ice losses.

Cooper LW, Ashijian CJ, Smith SL, Codispoti LA, Grebmeier JM, Campbell RG & Sherr EB (2006). Rapid seasonal sea-ice retreat in the Arctic could be affecting Pacific walrus (Odobenus rosmarus divergens) recruitment. Aquatic Mammals, 32, 98–102.

Comiso J, Parkinson C, Gerston R, Stock L. (2008). Accelerated decline in the Arctic sea ice cover. Geophysical Research Letters. 35 (1), 41-49.

Derocher, A.E., Lunn, N.J., and Stirling, I. (2004). Polar bears in a warming climate. Integrative and Comparative Biology, 44, 163-176.

Greenpeace. (2012). Climate Change Impacts on Arctic Wildlife. Technical Report. (Review), 3-14.

Simmons L, Firman R. (2014). Experimental evidence for the evolution of the mammalian baculum by sexual selection. Evolution. 68 (1), 276-283.

Sonne C, Dyck M, Riget F, Jensen JE, Hyldstrup L, Letcher R . (2015). Penile density and globally used chemicals in Canadian and Greenland polar bears. Environment Research. 137 (1), 287-291.

Sonne C, Leifsson P, Dietz R, Born E. (2006). Xenoendocrine Pollutants May Reduce Size of Sexual Organs in East Greenland Polar Bears (Ursus maritimus). Environ. Sci. Technol., 40 (18), 5668–5674.

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Is Forest Fragmentation The “New” Deforestation?

Posted on by Ariadne Wilkinson
Global Forest Fragmentation is destroying our most important ecosystems.
Global Forest Fragmentation is destroying our most important ecosystems.

 

It’s a well-known fact that deforestation is happening at extreme rates! Just look at the Amazon rainforest, where 20 football pitches worth of trees are removed every minute (Carrington, 2013). These global environmental changes are associated with our topic for today: fragmentation!

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WHAT IS FRAGMENTATION?

Forest fragmentation occurs when the total cover of a native forest is reduced. It is associated with anthropogenic deforestation, and leads to patchy forests and overall forest loss (Murcia, 1995) (Kupfer et al, 2006).

The isolated patches of forested habitats (remnants) in between the cleared forest cover follow the theory of ‘Island Biogeography’. Principles of Island Biogeography link forest fragmentation with biodiversity loss (Kupfer et al, 2006).

This is a good representation of forest fragmentation by Bacles & Jump (2011). The remnants have a drastically different ecosystem than their surroundings, just like an Island’s ecosystem is isolated from the outside world.
This is a good representation of forest fragmentation by Bacles & Jump (2011). The remnants have a drastically different ecosystem than their surroundings, just like an Island’s ecosystem is isolated from the outside world.

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FRAGMENTATION EFFECTS ON ECOSYSTEMS

 

– Microclimate Change (Saunders et al, 1991)

The microclimate within and surrounding the remnant forest is altered in the following ways:

More solar radiation. This restricts shade-tolerant species and encourages the spread of new species of plants (ex. vines, secondary vegetation) and animals to occupy the forest clearings and edges.

The accompanied temperature rise alters soil moisture and nutrient availability, modifying the local vegetation. It also disturbs species interactions and animal foraging behaviours (ex. Carnaby’s cockatoos).

Image by Georgina Steytler: A Carnaby’s Black-Cockatoo (Calyptorbynchus funereus latirostrus). Higher temperatures in fragmented cockatoo habitats reduced their foraging time available, which led to their local extinction in areas of Western Australia (Saunders et al, 1991)
Image by Georgina Steytler: A Carnaby’s Black-Cockatoo (Calyptorbynchus funereus latirostrus). Higher temperatures in fragmented cockatoo habitats reduced their foraging time available, which led to their local extinction in areas of Western Australia (Saunders et al, 1991).

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Stronger winds. Reducing the denseness of the forest leaves it more exposed to penetrating winds. That, amongst other things, changes vegetation structures and food availability for the forest communities.

Increased water flux. Fragmented forests alter the landscape through heavy water flows that erode the topsoil and transport more particulate matter across the forest cover.

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– Isolation (Saunders et al, 1991)

Remnant forest habitats are usually left crowded, with more species than they can actually support. Therefore, over time species will inevitably be lost due to the lack of resources and space available.

Species survival will generally depend on how well they can adapt to new conditions or migrate to new areas. The most rapid extinctions will occur for species with small populations, or ones that are heavily dependent on native vegetation or large territories.

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– Greenhouse Effect

Tropical rainforests store large amounts of carbon. Destroying them releases this stored carbon into the atmosphere and largely contributes to global warming (Laurance et al, 2002).

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MADAGASCAR

Fragmentation is a serious issue for this biodiversity hotspot, and its all due to human activities.

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Fragmentation is a major concern for Madagascar: The original extent of the eastern rainforest was around 3 times larger than what it currently is!

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Prior to human colonisation the forest on the eastern highland spine of Madagascar was 11.2 million ha, but by 1985 it only covered 3.8 million ha (Green & Sussman, 1990). (These satellite images can be found in Conservation Corridor).

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Its size is diminishing due to fires, illegal logging and agricultural deforestation (Ganzhorn et al, 2001).

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The forest on the Eastern Highland spine of the island is shrinking very fast. Forest can only survive within the gullies, where the fires can’t reach it. Image by: Josia Razafindramanana.
The forest on the Eastern Highland spine of the island is shrinking very fast. Forest can only survive within the gullies, where the fires can’t reach it. Image by: Josia Razafindramanana.

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Many larger species have been lost, and the remainder are unlikely to maintain viable populations beyond 2040. Populations of lemurs with fewer than 40 adults cannot survive. Worryingly, none of the remnant patches on the eastern Madagascar forest are large enough to maintain even such populations (Ganzhorn et al, 2001).

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Lemurs are holding on to the trees for dear life. The high rate of fragmentation is a major concern for these primates, as well as for all of Madagascar’s endemic forest ecosystems. Image by Frank Vassen
Lemurs are holding on to the trees for dear life. The high rate of fragmentation is a major concern for these primates, as well as for all of Madagascar’s endemic forest ecosystems. Image by Frank Vassen.

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THE ONLY SAVING GRACE: CONNECTIVITY

Corridors to connect remnants have proven useful when striving to enhance biodiversity.

They can aid the re-colonisation and immigration of species, provide refuge, and help with further species interactions (Saunders et al, 1991) (Laurance et al, 2002).

The size and shape of the remnants can also affect its vulnerability to external factors:

The best conditions for the conservation management of the ecosystems within remnant patches or forest (here they are termed ‘reserves’ from the “Island-like reserves” biogeography theory) can be seen in this image. The theory of forest connectivity is linked to this.

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Word Count: 499

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FOR MORE INFORMATION ON:

Fragmentation effects on ecosystems you can watch: https://www.youtube.com/watch?v=lzf-uX6kGkk

How Madagascar is managing its lemur populations you can watch: https://www.youtube.com/watch?v=ZhOyD79ymJA

 

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REFERENCES:          

          Carrington, D. (2013). Amazon deforestation increased by one-third in past year. [online] the Guardian. Available at: https://www.theguardian.com/environment/2013/nov/15/amazon-deforestation-increased-one-third [Accessed 18 Mar. 2017].

          Ganzhorn, J., Lowry, P., Schatz, G. and Sommer, S. (2001). The biodiversity of Madagascar: one of the world’s hottest hotspots on its way out. Oryx, 35(04), p.346.

          Green, G. and Sussman, R. (1990). Deforestation History of the Eastern Rain Forests of Madagascar from Satellite Images. Science, 248(4952), pp.212-215.

          Kupfer, J., Malanson, G. and Franklin, S. (2006). Not seeing the ocean for the islands: the mediating influence of matrix-based processes on forest fragmentation effects. Global Ecology and Biogeography, 15(1), pp.8-20.

          Laurance, W., Lovejoy, T., Vasconcelos, H., Bruna, E., Didham, R., Stouffer, P., Gascon, C., Bierregaard, R., Laurance, S. and Sampaio, E. (2002). Ecosystem Decay of Amazonian Forest Fragments: a 22-Year Investigation. Conservation Biology, 16(3), pp.605-618.

          Murcia, C. (1995). Edge effects in fragmented forests: implications for conservation. Trends in Ecology & Evolution, 10(2), pp.58-62.

          SAUNDERS, D., HOBBS, R. and MARGULES, C. (1991). Biological Consequences of Ecosystem Fragmentation: A Review. Conservation Biology, 5(1), pp.18-32.

 

 



Caring for the Community – How Climate Change is Impacting You!

Posted on by Kirsty State

Global warming has resulted in many species responding and behaving differently.  These changes can impact communities of plants, animals, people, in fact, all species that interact with each other within an environment.

Responses by different species to climate change are all connected through the interactions and shared resources of an ecosystem.  Overall earlier life events, such as flowering, feeding and hatching, are being recorded (Walther, 2010).  However, species do not respond equally to environmental changes.  This can result in timings of species interactions being off as a result of varying degrees of responses to temperature changes

The species found at certain locations are determined by three “filters”:

  • Dispersal
  • Environmental
  • Interactions

These filters are based around interacting species and their tolerance to specific environmental conditions (Götzenberger et al., 2012).  Global warming can be seen as an environmental filter (Weiher et al., 1998).  The increase in temperature could result in species being more or less tolerant of the increased temperature and therefore could change the collection of species in a community.

Climate change is occurring all over the planet, with certain ecosystems being particularly sensitive to it…

Take, for example, the tundra.  This is the area that borders the arctic, where species have to adapt to low temperatures with high variation.  Warming can result in many changes in this area.  Evidence from Alaska shows that climate change can influence land cover (Hinzman et al., 2005). This is through the increasingly more temperate climate, which allows species to grow in less hostile areas which were previously too cold or dry.

rein

Reindeer herd moving across their snowy calving grounds in the Mackenzie Delta, Canada (Dory, n.d)

Reindeer and Caribou species have been increasing in number in northern latitudes.  These play an important role in communities as they are often the largest, most numerous herbivores in an area.  As seen in the diagram below, the species are both affected by climate change impacts on the ecosystem as well as changing the ecosystem themselves.  Their impact on the environment has the potential to cause a vegetation transition (Bernes et al., 2015).  This could result in a knock on effect to other species that also feed off the vegetation eaten by Reindeer and Caribou.

flow-diagram

Flow diagram showing how increased temperatures affects vegetation and large herbivores

Another example is the plant-pollinator relationship that is disrupted by increasing temperature.  Both pollinators and the plants they pollinate, are changing their feeding and flowering times, respectively, at similar rates.  However, these rates are not exactly equal, resulting in a mismatch in the timings (Hegland et al., 2009).  Consequences of this mismatch are that pollination is not as efficient as it could be and that both plant and pollinators numbers are at risk.  This can have bottom up effect on the ecosystem, especially on species (such as humans) that rely on crops that are pollinated as a source of food (Walther, 2010).

bee-and-flower

Bumblebee pollinating a Dahlia ‘Moonfire’ plant (Photo by Kirsty State, 2015).

From these case studies it is important to note that not only is climate change impacting specific species that respond to temperature change, but through a network of communities and interactions within an ecosystem, it can indirectly affect us all.

 

 

Word count: 494

References

Bernes, C., Bråthen, K.A., Forbes, B.C., Speed, J.D. and Moen, J., 2015. What are the impacts of reindeer/caribou (Rangifer tarandus L.) on arctic and alpine vegetation? A systematic review. Environmental Evidence, 4(1), p.1-26.

Dory, N., n.d.  The reindeer of the Mackenzie Delta, Northwest Territories. [photograph] Available at: <http://www.nicolasdory.com/reindeer-of-the-mackenzie-delta/> [Accessed 17 March 2017].

Götzenberger, L., de Bello, F., Bråthen, K.A., Davison, J., Dubuis, A., Guisan, A., Lepš, J., Lindborg, R., Moora, M., Pärtel, M. and Pellissier, L., 2012. Ecological assembly rules in plant communities—approaches, patterns and prospects. Biological reviews, 87(1), pp.111-127.

Hegland, S.J., Nielsen, A., Lázaro, A., Bjerknes, A.L. and Totland, Ø., 2009. How does climate warming affect plant‐pollinator interactions? Ecology letters, 12(2), pp.184-195.

Hinzman, L.D., Bettez, N.D., Bolton, W.R., Chapin, F.S., Dyurgerov, M.B., Fastie, C.L., Griffith, B., Hollister, R.D., Hope, A., Huntington, H.P. and Jensen, A.M., 2005. Evidence and implications of recent climate change in northern Alaska and other arctic regions. Climatic Change, 72(3), pp.251-298.

Walther, G.R., 2010. Community and ecosystem responses to recent climate change. Philosophical Transactions of the Royal Society B: Biological Sciences, 365(1549), pp.2019-2024.

Weiher, E., Clarke, G.P. and Keddy, P.A., 1998. Community assembly rules, morphological dispersion, and the coexistence of plant species. Oikos, 81(2), pp.309-322.



Popeye didn’t cause the spinach shortage: why the effects of global environmental change on plant function is a double-edge sword

Posted on by Anonymous

Climate change – a myth? We have all heard of it and its impending threat to our global environment. However, what we should ask ourselves is how are plants affected by our planet’s increasing temperatures, carbon dioxide (CO2) levels and the increasing frequency and intensity of severe weather changes?

Diagram illustrating some factors mentioned that are linked to climate change and their impact on several biological processes carried out in plants
Diagram illustrating some factors mentioned that are linked to climate change and their impact on several biological processes carried out in plants (Source: (Kallarackal and Roby, 2012))

Plants play a critical role in pulling CO2 out of the atmosphere. This uptake of CO2 during photosynthesis is a major pathway by which carbon can be stored (Tkemaladze and Makhashvili, 2016). Carbon dioxide is predicted to increase to approximately 1000 ppm by 2100. Since the beginning of the Industrial Revolution approximately 200 years ago average global temperatures have increased by 0.85°C and by the end of the century temperature is projected to rise by approximately another 4°C (IPCC, 2013).  Some would assume this to be beneficial to plants due to these warmer temperatures and increased levels of gas as it should, in theory, encourage growth. However, it is not as straight forward as this.

The enzyme rubisco is the key to this photosynthetic process by fixing CO2. Drake et al. (1997) states that the increased levels of CO2 will allow greater fixation by plants and, therefore, result in increased growth. However, Bisgrove and Hadley (2002) found that long-term exposure to elevated levels of CO2 caused an accumulation of carbohydrates in plant tissues, which in turn reduced the rate of photosynthesis. Furthermore, although plants initially respond positively to increasing temperature, this will eventually plateau or even decline after reaching the optimum range for some species. Plants may experience an increased rate of respiration leading to death; illustrating the world’s plants can easily lose their ability to act as a global carbon sink, becoming instead yet another carbon source (Mellilo et al., 1990; Hawkins et al., 2008).

Moreover, another consequence of global environmental change is a change to global weather patterns. Many do not connect climate change with uncharacteristic weather events, however, there is no doubt that climate change affects their intensity and frequency. Thus, in the future, we can expect to experience more frequent periods of drought, floods and storms (Frich et al., 2002). For example, during the past winter, there was snow escape in Spain as we witnessed a window to our future in the form of the courgette and spinach crisis, which caused havoc and rationing in British supermarkets. Yet these changing weather patterns will have a much larger impact than just a blow to spiralizer sales.

 

The heavy snowfall the province of Murcia in Spain experienced this winter ruining many crops.
The province of Murcia in Spain experienced heavy snowfall this winter ruining many crops (Source:http://edition.cnn.com/2017/02/03/europe/lettuce-shortage-europe/)

Stated above are only a few effects global climate change has on our planet’s plants. Plants have an essential regulatory role in the control of our planet’s climate: they did yesterday, they do today and they most certainly will in the future. If we continue to allow the CO2 level to increase at the rate it is currently we will suffer dramatic consequences. It not only will affect the Earth’s vegetation such as forests and plants, but will also have a knock-on effect on global food production, therefore, affecting our wellbeing.

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References

Bisgrove, R. and Hadley, P. (2002). Gardening in the global greenhouse: The impacts of future landuse and climate on the red list status of the Proteaceae in the cape floristic region, South Africa. Global Change Biology, 69, pp.79-91.

Drake, B., Gonzàlez-Meler, M. and Long, S. (1997). More efficient plants: A Consequence of Rising Atmospheric CO2?. Annual Review of Plant Physiology and Plant Molecular Biology, 48(1), pp.609-639.

Frich, P., Alexander, L., Della-Marta, P., Gleason, B., Haylock, M., Klein Tank, A. and Peterson, T. (2002). Observed coherent changes in climatic extremes during the second half of the twentieth century. Climate Research, 19, pp.193-212.

Hawkins, B., Sharrock, S. and Havens, K. (2008). Plants and climate change; which future? Richmond, UK: Botanic Gardens Conservation International, pp.98.

IPCC (2013) Climate Change 2013: The Physical Science Basis.Intergovernmental Panel on Climate Change, Cambridge, UK.

Kallarackal, J. and Roby, T. (2012). Responses of trees to elevated carbon dioxide and climate change. Biodiversity and Conservation, 21, pp.1327-1342.

Melillo, J., Callaghan, T., Woodward, F., Salati, E. and Sinha, S. (1990). Effects on Ecosystems, in Climate Change: The IPCC Scientific Assessment, edited by J. Houghton, G. Jenkins, J. Ephraums, Cambridge University Press, Cambridge, pp.283−310.

Tkemaladze, G. and Makhashvili, K. (2016). Climate changes and photosynthesis. Annals of Agrarian Science, 14, pp.119-126.