Curbing Climate Change: Update
IPCC releases its third report of the current series - on 'climate mitigation'.
Spoiler: The news stories out there on this report are not the ones I would write. I share my own version of the story towards the end of this post. But first a bit of background on the IPCC and why it matters.
The Intergovernmental Panel on Climate Change (IPCC) is the most authoritative international body assessing and reporting on all aspects of climate change. It’s overseen by the United Nations and includes thousands of authors from all over the world. It’s a very impressive effort and has been incredibly effective at providing the information that drives global and national policies.
Way back in 1990, the IPCC released its First Assessment Report, and this year, we’re reading the Sixth Assessment Report. For each series of assessments, the findings have become more robust (meaning there have been more and better data to work with), often more certain (the data all tend to point in the same direction), and the projected impacts more devastating.
But overall, the story hasn’t changed: Humans are releasing more greenhouse gases, which is causing the atmosphere to warm, which also causes many more changes, including heavier rainfall, rising sea levels, and higher rates of evaporation from soil and water bodies. All that extra carbon dioxide is also changing the chemistry of the oceans, making it more acidic. All of this leads to some seriously negative impacts for humans, the environment we rely on, and the rest of the natural world.
The science has been startlingly consistent throughout the last 30 years or so of global climate assessment - if anything, underestimating the changes we’ve seen over that span.
Following the pattern of recent assessments, the sixth one is broken down into three main reports (plus a synthesis that will be released late this summer).
The first report was on the physical basis for climate change (all about the science and the Earth system)
The second report was on the impacts of climate change along with documenting specific vulnerabilities (in cities, ecosystems, agriculture, energy etc) and measures we can take, and are already taking, to adapt.
And the one released this week, the third, is on the options for mitigating climate change, including the consequences for different scenarios of how much and by when we reduce carbon dioxide in the atmosphere.
It is critical we keep up to date with the changes we’re seeing, their impacts, and the progress we are making (or failing to make) towards moderating our influence on climate change. I do believe that the history of the 21st Century will be written with climate change as the central challenge humanity accepted and (eventually) addressed (fingers seriously crossed on this one!) And the IPCC is a good place to read the latest updates (although even the summaries designed for lay people are written in somewhat policy-wonk language).
I have been a climate scientist for over 20 years at this point and was a PhD student in Massachusetts when the Second Assessment Report came out in 1996. I have followed each one and my research has even been used in it. I then had the privilege of leading the technical office of our US national version of the assessment, and so I am very familiar with the process of the assessments, their incredible power to evaluate what we know and project into the future, as well as their limitations.
And…..I confess I am a bit weary of the tale they apparently tell (but not so much the tale they actually tell).
The headlines from this latest one all seem a bit predictable to me. ‘It’s now or never’ to limit warming, says the BBC, and the Guardian, and ‘scientists issue ultimatum’ at CNBC. (However, Fox News is much worse: by finding the only commentator who continues to insist that hey, warming might be great, they embarrass themselves. I’m not even linking to their coverage - their ‘news’ is not.)
I get what these stories are sharing - the urgency and the magnitude of the climate change IS immense. And we had better get some serious and rapid momentum in reducing emissions if we are to avoid the worst of the impacts.
But clearly the ‘never’ in ‘now or never’ isn’t true. There is no ultimatum. And getting caught up in the drama of the press is not helpful. In fact, it’s damaging - it’s almost like crying wolf, because we get desensitized by the sensational nature of the messages. We either tune out or become hopeless.
If you read the actual headlines from the IPCC, there is certainly the sense of urgency, but there’s also a lot of progress to report and build on. So, here are my takeaways from the report:
By limiting fossil fuel infrastructure to what is currently active and currently planned, we can keep warming to about 2 degrees C. (This is a far cry from what would be the case with unabated fossil fuel development.)
The Paris Agreement and other individual commitments are reducing emissions from where they would otherwise have been. It isn’t enough to keep us below 1.5 C temperature rise (we are already around 1C), and it will need to get significantly more aggressive if we are to limit the rise to 2C (including no more fossil fuel development than currently planned - as above). Currently, the agreements as written would still allow around 3C of warming. This is basically unacceptable. However, the Paris Agreement is structured so that commitments would get more aggressive over time - this is already the plan.
The growth of emissions is slowing. That doesn’t mean emissions are declining, but they are rising less fast. We need to turn that into a decline (quickly), but this is an important step. We can’t get to a decline without first slowing the increase. And at least 18 countries have seen emissions reductions that have been sustained for longer than 10 years. That shows us what’s feasible.
The cost of low-carbon energy technologies have fallen consistently, meaning it’s more affordable for wider deployment of solar and wind, for example. There are equity issues with who can access this tech still and the IPCC point out that the financing of low carbon technology (as well as adaptation to the climate changes we can’t avoid) for less-developed nations is still weak and lagging commitments.
There is clear evidence that farming techniques that manage carbon in the soil better (e.g. no tilling and different or no fertilizer) can turn land from a carbon source to a carbon sink. That could be huge in drawing down carbon already in the atmosphere.
So I’m still highlighting that we need to do a lot more, and we need to do it soon, but we have successes to build on.
We now have to make improvements, which feels more doable (not easy, but doable). We’re not starting from scratch.