The Intergovernmental Panel on Climate Change has now published the first part of its Fifth Assessment Report, AR5. It says humanity is largely responsible for the recent warming of the Earth, it re-tells the Panel’s familiar story of rising temperatures and sea levels, of melting glaciers and ice sheets. Described by some as “conservative” and “telling us what we know already”, it’s also won some plaudits. These are some – not all unalloyed.
Dr Saleemul Huq is senior fellow in the climate change group at the International Institute for Environment and Development, and coordinating lead author in Working Group II of the IPCC.
“”The IPCC has confirmed what many millions of people in the developing world are well aware of, namely that the weather patterns have already changed for the worse. People in richer countries are vulnerable too, as recent floods, droughts and storms in Europe, North America and Australia have shown, but because of political inertia and powerful vested interests that have dominated media narratives for decades, they are less aware of the links between these impacts and their carbon emissions. Climate change affects us all and we must tackle it together. The time has come for global solidarity. This would enable the individual polluter (be they in a rich country or poor country) to recognise his or her personal responsibility and to try to connect with the victims of their pollution. Climate change ignores borders, but so do friendship and solidarity. It is time for national interests to give way to the global good. I hope the strong message from IPCC will galvanise actions by politicians and publics around the world.”
Dr Geoff Jenkins is the former head of climate change prediction at the Hadley Centre for Climate Prediction and Research, part of the UK Met Office.
“Attention has already been focussed on the ‘attribution statement’, in other words how far we can claim that warming over the last 50 years is due to human activity. There has been been much new research into attributing changes, not just at the surface but within the oceans, through the depth of the atmosphere, and in other parts of the climate system. This has allowed the IPCC to increase its confidence since [its last report in 2007] AR4 that humans bear most of the responsibility, and it now says it is extremely likely (above 95%) that human influence has been the dominant cause of the observed warming since the mid-20th century. I was surprised that the Summary for Policymakers didn’t spend more time talking about the recent pause in warming; this has given rise to a lot of media commentary and genuine scientific discussion (including three excellent position papers on the Met Office website). Given its target audience – policymakers – this topic should have been covered in more detail in the report.
“The sensitivity of the climate system to atmospheric carbon dioxide has changed slightly since AR4, with the top of the range of uncertainty staying at 4.5C, but the lower bound dropping from 2C to 1.5C. The 1.5 – 4.5 range is identical to that in the very first IPCC report in 1990, demonstrating the robustness of the global projections from then.
“Comparing predictions of global and local temperature rise with those in AR4 is made difficult by the introduction of completely new scenarios with which to drive the models. However, the report says that when these differences are taken into account, AR4 and AR5 show similar changes, both in rate and geographical pattern.”
Paulo Artaxo is professor of environmental physics at the University of São Paulo, Brazil. He served on working groups on both the previous and present IPCC Assessment Reports.
“What I call the good news is that the predictions made in the last assessment report are – in general terms – broadly in line with what we record in the present report. Our basic forecasts for temperature rise have been proved to be correct. There is a maturity and increasing sophistication in our processes. The science is very, very clear – the urgency to cut emissions is much stronger than when the last report was being formulated. Both the IPCC and our own climate model (the Brazilian Earth System model) indicate the overall temperature increase by 2100 in Brazil will exceed the forecast average rise in global temperatures. The northeast of Brazil will see the largest increase in temperatures and the biggest decrease in precipitation – of about 30%. Meanwhile precipitation could increase by a similar amount in the south and southeast. All this is likely to have a big impact on Brazil as a major agricultural producer. We are already observing changes in crop yields due to changing temperature and rainfall patterns, particularly in relation to soybean, coffee and sugar cane production. For example, because of an average 1°C rise in temperatures in the São Paulo region in recent years, coffee has become increasingly hard to grow and the crop has declined. The main message of this report is that the global political system has to develop a way to limit emissions. There is a serious lack of governance and this blocks international agreements. The report must feed into the political system – and be urgently acted on.”
Quamrul Chowdhury is a lead climate negotiator for the Least Developed Countries at the talks held by the UN Framework Convention on Climate Change.
“The first part of AR 5 has just reconfirmed what the Least Developed Countries have been arguing at the UN climate negotiations for the last couple of years. Global carbon emissions need to be cut deeply and urgently. This IPCC report asks all of us to act fast, act in a more robust way, act together, act all over the world. The developed countries must take the lead – cut back their carbon emissions quickly and deeply, support concrete adaptation in the developing countries, specifically in the LDCs, SIDS [small island developing states] and African countries affected by drought, flooding and desertification. I earnestly hope this report will help raise the political will of the developed countries to strike a deal in Warsaw at [the next UNFCCC talks in November] so that in Paris [at the climate talks] in 2015 the world can reach a new legally binding, fair and ambitious agreement to solve the global climate crisis.”
Nick Robins is head of the Climate Partnership at HSBC.
“The IPCC report provides firmer foundations for policy action. For the world’s capital markets, climate change is an issue of strategic risk management – and by continuing to pump greenhouse gases into the atmosphere, we are putting the weather on steroids. We know that temperatures continue to warm and that impacts are fully in line with what we would expect from a warming world, including rising sea levels and melting glaciers. And this is affecting economies today. Our research shows that India, China, Indonesia, South Africa and Brazil are the G-20 nations that are most vulnerable to climate risks. We expect the succession of IPCC reports into 2014 to provide a renewed impetus to policy and business action through to the finalization of negotiations in December 2015.”
Mark Way heads re-insurer Swiss Re’s sustainability work in the Americas.
“When a body like the IPCC concludes that with 95% certainty mankind is causing climate change we would be foolish not to listen. And yet we are still not listening closely enough. The transition to a low carbon economy and a more climate-resilient society cannot be thought of as options, they are necessities. Swiss Re is committed to playing its role in tackling climate change, and we have just reinforced this by announcing we will join an initiative that pledges companies to source 100% of their energy needs from renewable sources by 2020.”
Mindy Lubber is president of Ceres, a US-based organisation which presses for greater sustainability and environmental awareness in the business sector:
“The IPCC report’s conclusion is unequivocal – climate change is happening and it’s disrupting all aspects of the global economy, including supply chains, commodity markets and the entire insurance industry. Business momentum is growing to innovate new strategies and products to manage climate risks and opportunities. But scaling these efforts to levels that will slow warming trends will require stronger carbon-reducing policies globally.”
