World Environment Day: Tackling climate change requires systems thinking and collective action

Bn-51-MIcAAa__PYesterday’s World Environment Day, the United Nations’ principal vehicle for encouraging worldwide awareness and action for the environment, focused on tackling climate change. This year’s theme is Raise your voice, not the sea level. First established in 1972, every year on 5th June countries around the world host seminars, events and environmental projects from cleaning up Kosovo to solar electric roofs in Barbados to plastic purges on the beaches of Sri Lanka. And there are the WED challenges.

This year is also the UN International Year of Small Island Developing States (SIDS) and part of the activities of WED were to raise awareness about the challenges SIDS face, their vulnerability to climate change and sea level rise and the urgent need to help protect the islands.

The message of WED is that our individual actions will aggregate into collective action with the power to transform, in this case mitigating climate change and its impacts. A draft of the IPCC 5th Assessment Report “Climate Change 2014: Mitigation of Climate Change” recently released, supports this message stating that “effective mitigation will not be achieved if individual agents advance their own interests independently”. Emissions in one area, sector or emitted by one person have broader impacts for others. Greenhouse gas emissions largely produced in developed countries and emerging economies are putting small island states at risk, a problem requiring collective action.

The IPCC report states that without additional mitigation, global mean surface temperature increases by 2100 will be between 3.7 °C and 4.8 °C compared to pre-industrial levels (the range is 2.5 °C to 7.8 °C when including climate uncertainty). Agriculture, forestry and other land uses (AFOLU) contribute 24% of total direct GHG emissions, second only to electricity and heat production which accounts for 25% (followed by Industry at 21% and transport at 14%).

In order to increase the chances of maintaining global average temperature increases at below 2°C, atmospheric concentrations of CO2 need to be around 450ppm in 2100. Scenarios achieving this target all have reduced GHG emissions, by 40% to 70%, by the middle of the century and emissions near zero GtCO2 eq or below in 2100. Such scenarios represent significant opportunities for improving air quality, energy security, human health and ecosystem resilience but many trade-offs and co-benefits have not been identified or quantified and climate policies will need to be assessed both on their potential to help mitigate climate change and by their effects on sustainable development, poverty eradication and equity. [Read more…]

Declining crop yields and increasing agricultural emissions

ID-100148476Alongside the recent release of the UN IPCC Fifth Assessment Report, a new study, published in Nature, provides evidence that global increases in temperature of only 2°C will reduce crop yields in temperate and tropical regions from the 2030s onward.

The meta-analysis, collated and analysed by researchers at the University of Leeds, combined 1,700 published data sets for wheat, rice and maize, the largest dataset on crop responses to climate change yet. The research, taking into account currently practiced adaptation activities such as changing planting dates and using improved varieties, as well as uncertainty and the timing of impacts, found that the variability between crop yields in different places and at different times is also likely to increase with climate change, which could have a profound impact on the security of food supply.

Beyond 2050 declines in crop yields will be greater in magnitude, reductions of 25% are expected to be widespread with median crop yields to drop by 2% each decade for the rest of the century. Although crop productivity has previously been predicted to improve in Northern Europe, crop yields even under moderate future warming may decline in many places. Coupled with increasing demand for food (expected to increase 14% per decade until 2050), future food security without significant intervention looks bleak.

The clear message from the paper and the IPCC Fifth Assessment Report is the urgent need for farmers to adapt to a changing climate and for all countries to seriously engage in mitigating climate change. The UN Food and Agriculture Organisation recently released figures showing that greenhouse gas emissions from the agricultural, forestry and fisheries sector have doubled over the last 50 years and could grow by over 30% by 2050. The majority of this increase is being seen in developing countries, with the expansion of agricultural production.

Between 2001 and 2010 emissions from crop and livestock agriculture increased 14% while emissions from land use change and deforestation declined 10%, yet more evidence that agriculture needs to be part of climate discussions. Within agriculture, enteric fermentation (methane from livestock) accounts for the largest proportion of emissions (39%) and increased 11% between 2001 and 2010. The FAO, in 2012, launched the FAOSTAT emissions database, which details the GHG emissions of agriculture, forestry and other land use activities.

With crop yields expected to decline (and already declining in many countries) and agricultural emissions appearing to be on an upwards trajectory, the former perhaps incentivising the latter, we need smarter agriculture, that is resilient to future climate change while also reducing GHG emissions, the very goal of sustainable intensification.

ID-100144969A recent paper in the Proceedings of the National Academy of Sciences, Climate change mitigation through livestock system transitions, discusses how climate mitigation policies can reduce emissions from the livestock sector. Authors identify much potential to mitigate climate change in livestock production systems, namely the transition from extensive to more productive systems, reducing the livestock sector’s impact on land use change. The paper also recommends emissions reductions should be targeted to the supply (rather than demand) side. Aside from this rather controversial recommendation, this paper, as with many others, identifies significant opportunities to mitigate climate change and increase food supply within the agricultural sector. Serious action on implementing the variety of adaptation and mitigation strategies at the global and local level appears to be the limiting factor in progress.

Africa’s Adaptation Gap

ID-10042579A recent technical report published by the UN Environment Programme, the African Ministerial Conference on the Environment (AMCEN) and Climate Analytics investigates the impacts of climate change and the costs of adaptation in Africa. Africa’s Adaptation Gap report  is a warning to policymakers of both the implications for Africa should global mitigation activities fall short as well as the urgent need for scaling up adaptation activities and funding in this continent, a region the IPCC’s Fourth Assessment Report named a “vulnerability hot spot” for the impacts of climate change.

Africa is projected to experience severe climatic changes compared to historical conditions: more frequent extreme weather events; sea level rise of over one metre with global average temperature increases of 4°C by 2100; significant decreases in precipitation across many areas; a loss of biodiversity and potentially grazing area; and maize, millet and sorghum growing areas are likely to become unviable with global average temperature increases of 3°C as growing seasons shorten and optimal heat ranges are exceeded..

The report summarises the estimated costs of adaptation Africa faces under different scenarios:

  • With current emissions levels, adaptation costs will be $7 to $15 billion per year to 2020.
  • If we close the emissions gap to hold average global temperature increases to below 2°C, costs will be $35 billion per year by 2050 and $200 billion by 2070, although a large degree of uncertainty exists.
  • If we continue on our current emissions trajectory, and global average temperatures rise by 3.5-4°C by 2100, adaptation costs could be $50 billion per year by 2050 and $350 billion by 2070.

These adaptation costs will include such things as early warning systems, coastal protection, drought-resistant crops, irrigation, desalinisation and infrastructure protection, and, as the report shows, will be significant even with immediate emissions reductions. The report illustrates the critical link between developed country mitigation activities and the financial burden of adaptation in Africa, a burden that could constrain economic development. [Read more…]

IPPC 5th Assessment Report

IPCCcoverOn the 30th September the Intergovernmental Panel on Climate Change (IPCC) launched the first part of their 5th Assessment report, the 4th having been published in 2007, which analyses and synthesises the latest data, projections and physical evidence for climate change. The dominant message from the report from working group I of the IPCC is that scientists are surer than ever that climate change is due to human related activities.

The contributions of working groups II and III, and the overall synthesis report are to be published sequentially ending in October 2014.

The IPCC, which provides “a clear scientific view on the current state of knowledge in climate change and its potential environmental and socio-economic impacts”, has convened over 800 climate scientists from around the world to produce a landmark report on the state of climate change in the world. We summarise some of the key findings here:

  • It is extremely likely that human influence has been the dominant cause of global warming since the mid-20th century. Over half of the increase in global surface temperatures between 1951 and 2010 can be attributed to human activities.
  • The period from 1983-2012 in the Northern Hemisphere was probably the warmest 30-year period of the last 1,400 years.
  • Projections of the highest emissions scenario show an increase in the global average temperature of 4°C by 2100. With significant emissions reductions, the report explains, global temperature increase can be limited to below 2°C but with a doubling of CO2 in the atmosphere, we are likely to see an average change in temperature of between 1.5°C and 4.5°C. Warming above 2°C is considered a critical threshold above which we can expect “dangerous” impacts.
  • The report warns of the long lasting effects of greenhouse gas emissions, which will remain in the atmosphere and warm the climate for centuries to come even with immediate and significant mitigation activities. Some 15% to 40% of released CO2 will remain in the atmosphere longer than 1,000 years after those emissions have ended.
  • Sea levels are expected to rise faster than in the last 40 years. In this century, sea levels are projected to rise between 26cm and 82cm, dependent on greenhouse emissions.
  • The Gulf Stream (or Atlantic Ocean circulation) is expected to weaken by 12% to 54% by the end of the century.
  • Over the last two decades, the Greenland and Antarctic ice sheets have been shrinking. The report states that if emissions continue unabated the Arctic Ocean will likely become virtually ice-free in summer before the middle of the century.
  • It is “virtually certain” that sea level rise will continue beyond 2100 and sustained warming above some unknown threshold will lead to the melting of the Greenland Ice Sheet, which would cause a global mean sea level rise of up to 7m. The total loss of the Greenland ice sheet is estimated to occur at 1 to 4°C of warming above preindustrial temperature.
  • The atmospheric concentration of carbon dioxide (CO2) has increased by 40% since pre-industrial times. Average increases in CO2, methane (CH4) and nitrous oxide (NO2) are believed, with high confidence, to be far higher than increases occurring in the last 22,000 years.
  • The recent slowing down of temperature increases, seen in the last 15 years, is not considered a long enough timescale to come to any conclusions.

Although these findings are worrying enough, to achieve this consensus around the physical impacts of climate change, the estimates can be considered conservative.

For many, who have already accepted human-induced climate change, there is a less of a question of what is physically happening and more of a concern over what we are going to do about it. We will have to wait for the next instalments of the IPCC 5th report and hope that their impact is significant enough to motivate the world to act.

Where are we on climate change?

ID-100103034 (2)Professor Sir Brian Hoskins, Director of the Grantham Institute for Climate Change and advisor to the UK government through the Committee on Climate Change, recently gave a talk at Imperial College London on the latest research and actions around climate change.

Global CO2 levels are currently at 397ppm (parts per million), a level not seen for 4.5 million years. We have increased CO2 levels in the atmosphere by 40% since the Industrial Revolution. While there has been a clear and significant increase in global temperatures since 1850, we have seen a hiatus on temperature rises in the last decade. While sceptics may use this as evidence to support their claims, a decade of cooler temperatures is not outside the range of predictions from climate models.

Global sea levels are rising 3mm per year. While the melting of the Western Antarctic and Greenland ice sheets is contributing around 1mm of this increase, it is unknown how likely this is to accelerate if we reach a threshold point of destabilisation. In the Arctic, recent pictures of the ice cap in mid-September (when it is at its minimum size) show it is half the average size it was in the last century. By 2050-2060 we would expect the arctic ice cap to have vanished come September.

We have seen some significant heat extremes in the past decade: the 2003 European heatwave, 2010 Russian heatwave and more recently the 2012 US drought. Work by NASA scientists Dr James Hansen and colleagues indicates a shift to more frequent and severe bouts of high temperatures. But it is not just heat extremes, as the climate changes we are also seeing cold extremes in certain locations despite remarkable warmth elsewhere. This indicates our ability to predict regional trends is much more limited than our ability to predict global averages and while we may, in the past have viewed climate change as a warming of the planet, now we are trying to understand it as a disruption of our climate systems, one that will have severe and varied results. [Read more…]