Almost everyday we see a lot of reports regarding climate change being published or re-published. On September 27 The Gurdian has published an article in which we can read another point of view. A scientist describes her week in Stockholm, where she and colleagues were approving the science in the most important climate change report ever written.
“I have spent this week in Stockholm, going through the laborious but fascinating process of approving the Summary for Policymakers of the IPCC [Intergovernmental Panel on Climate Change] Working Group I report, the most comprehensive scientific assessment of climate change written to date.
The report is science meets policy. I’m on the science side. With my 259 colleagues, we spent three years writing this report, went through two rounds of reviews, considered nearly 55,000 comments, and wrote more than 1,000 pages of detailed scientific analysis that forms the basis of the scientific consensus on climate change. For policy, all this has been condensed into 18 key statements, 20 pages and nine figures, this week discussed line by line by delegates of the 111 countries represented here in Stockholm. This makes me nervous.
Unbelievably, while out here, I read that according to some UK and Australian news the Arctic ice extent has recovered this year!? Who made that up? The changes taking place in the Arctic are astonishing. Its September cover has shrunk from 7.5 million square km in the early 1980s to 4.6 million square km in the past five years.
I’ve been following the Arctic ice cover for some years, and it’s melting. The 2007 September ice cover took us by surprise, it was so small. Everyone said then that this was an unusual year, so as September arrived in 2008 I looked every day at the record to see when the ice would start freezing again as autumn set in. Indeed, the ice extent went up a bit and wiggled up and down the following two years. But sure enough, when September 2012 arrived, Arctic ice cover broke a new minimum record yet again, in line with the 30-year trend of melting and shrinking.
‘Climate is what you expect, weather is what you get’ (quoted, I think, from Mark Twain). It is tempting to focus on unusual weather here and now, and to conclude that it’s somehow representative of the global climate trends. It’s so intuitive to interchange weather and climate that this is heavily exploited by people who want to make a point on either side of the climate change debate: a cold winter provides ammunitions for “downplayers”, while a heatwave provides ammunition for “alarmists”. The scientists sit in the middle, trying to extract the contribution of climate change from that of the background natural variability in weather, an exercise that has limits, takes time, and usually comes too late.
So we spent the week in Stockholm completing the most comprehensive report on climate change to date, and there is a slowdown in global warming. It’s not the first slowdown we’ve had, but this one is under scrutiny given the politicisation of the issue. Just as the weather changes year on year, climate is also influenced by the natural environment. Volcanic eruptions cool the planet, and we’ve had a dozen smallish volcanoes since 2005. Remember the Icelandic volcano that paralysed European air traffic for six days in 2010? The warmth of the Pacific Ocean oscillates naturally, and it is currently on the cool side. Same for the sun, it gets hotter and cooler every 11 years more or less. Not much, but that’s what we are talking about here – small changes on top of very evident long-term trends. These are temporary effects observed in surface warming of Earth. Yet the climate system has continued to gather energy: the ocean below the surface has continued to warm, snow and ice have continued to melt, and the Arctic ice extent has continued to shrink.
The recent slowdown in surface warming is one of the many parts of the complex and interconnected puzzle that was discussed last week. With each assessment we have a longer time period of observations, more data from satellites, a better understanding of the human influence on climate, and better methods to detect it. So confidence builds up through time, as new evidence accumulates. The main conclusions in this report are thus strengthening what we already know: that we are more certain than ever that human activities are causing global climate change.
Our job, as scientists called into the IPCC, is to examine all the evidence, and to make it accurate and understandable. Every word in this Summary for Policymakers is carefully considered and based on the underlying 1,000-page report. I’m nervous because there is pressure from people on either side of the debate, and deliberate efforts by some to make us look as if we have a political agenda, rather than an evidence-based objective opinion.
Our only agenda is to communicate the findings of all the science, and to provide the best information possible to ensure that policy decisions on climate change are based on reality. That’s the purpose of the Summary for Policymakers: we pass the baton from the scientists to the policymakers.
Our job is done now and it is time to let the policymakers do theirs. Yes, I’m hoping that they will consider the weight of our science, but I’m very conscious that their decisions take into consideration many other linked issues. In November, the governments of the UN Framework Convention on Climate Change will gather for their annual summit, this year in Warsaw. Together and individually, countries will either drop or carry forward the baton. My hope is that they do not ignore the science entirely as they negotiate international climate policy, because climate policy requires a long-term view and the best data available.”
- Scientists Call for Overhaul of IPCC (insideclimatenews.org)
- Climate Change Scientists Struggle Over How to Address Recent Slowdown in Global Warming (theblaze.com)
- IPCC report: Scientists are 95% certain humans are responsible for climate change (independent.co.uk)