Statement from Nicholas Stern on criticism of the IPCC
Commenting on the latest media coverage and criticism of the Intergovernmental Panel on Climate Change, Nicholas Stern, chair of the Grantham Research Institute on Climate Change and the Environment at London School of Economics and Political Science, said:
“It is a fundamental part of the scientific method that researchers should publish their work so it can be examined by their peers. Since the Fourth Assessment Report of the Intergovernmental Panel on Climate Change was published in four volumes in 2007, it has been under intense scrutiny. It is perhaps not surprising that some isolated errors have been found within the 3000 pages of the report, but it is noteworthy how comparatively few there are.
“It is also important to note that the errors that are now being highlighted nearly three years after the IPCC report was published appear to occur only within its main body and not within the summaries that outline the main findings. Not all of the criticisms of the IPCC report have been substantiated. Where errors have been found, the IPCC has quite rightly issued statements and errata to correct them. These corrections relate to details of the local impacts of climate change, and do not affect the overall pattern of observations or the fundamental science.
“It is striking that the few errors in the IPCC report are now receiving extraordinary media coverage, while the literature promoted by so-called ‘sceptics’, which contain numerous and substantive mistakes and misrepresentations, remains largely free of critical scrutiny. When confronted with their glaring misrepresentations of the science of climate change, the ‘sceptics’ offer neither acknowledgements nor corrections, but instead attempt to deny or distract.
“The main findings of the IPCC report remain clear and unaffected by the recent criticisms. The Earth is warming in response to rising levels of greenhouse gases in the atmosphere, due to human activities such as burning fossils fuels and deforestation. The fundamental science of climate change is founded on a body of evidence that has grown since Joseph Fourier in 1824 described the basics of the greenhouse effect whereby the Earth’s atmosphere makes the surface of the planet warmer than it otherwise would be. This was followed in 1861 with the publication by John Tyndall of the results of experiments in which he identified those molecules in the atmosphere, such as carbon dioxide, that create the greenhouse effect. None of the current accusations against the IPCC have undermined this solid basis of nearly 200 years of research.
“What is also clear is that if we carry on with current and rising rates of greenhouse gas emissions, concentrations in the atmosphere could rise from the current level of about 435 parts per million to around 750 parts per million or more by the end of the century. The human species has no direct experience of such atmospheric concentrations, but physicists have calculated that there is a significant chance that global average temperature would rise by 5˚C or more, levels not seen on Earth for more than 30 million years. Such a rise in temperature would have a profound impact on the climate and on the physical geography of land and sea across the world, affecting the lives and livelihoods of billions of people, and particularly where people could live.
“Of course there are important uncertainties and many scientific issues that remain open. But the underlying risk from the accumulation of greenhouse gases points, on the basics of physics and the wealth of evidence, to the existence of major risks. Given what we know about the process of accumulation of greenhouse gases, delay is likely to be dangerous.
“These are issues of risk management. Are these risks that we are prepared to take, given that there is much that we can do to reduce them, and where those actions have important benefits beyond those of climate change, offering major opportunities for growth, investments and jobs?
“Are those who argue for inaction or delay in tackling greenhouse gas emissions very confident that these risks are negligible or zero? If so, where is the evidence?
“There are fundamental choices and decisions we have to make now on the basis of our current understanding of the risks, and upon which the future of our children and future generations depends. And the longer we wait, the bigger those risks will grow.”