One of the advantages of the planetary boundaries perspective is that it puts climate change in a wider context, as one of a set of boundaries, rather than as the only ecological issue worth talking about.
However we should not lose sight of the fact that climate is clearly the Number One boundary both in terms of its current urgency and the consequences of exceeding it.
The latest report from IPCC is an updated overview on the impacts of climate change and the possibilities for adaptation. The report comes from Working Group Two of IPCC, and is its contribution to the IPCC Fifth Assessment Report, which has gained added significance through being the key science input to next year’s important global climate conference in Paris (Nov 30 to Dec 11).
The report doesn’t paint a very different picture from the ones we have seen before. It reaffirms the seriousness, urgency, and potentially devastating impacts of man-made climate change. However some points stand out from it as, in my view, particularly interesting –
• The advance of research in this field has led to greater understanding of climate change impacts in particular continents and regions. This makes for a less dramatic report in some ways, because there are less global generalisations, but on the other hand, there is much more useful detail.
• The report indicates some shift of interest towards adaptation. Obviously climate change still needs to be stopped or slowed down, but at the same time, we can’t get away from the fact that it is already happening, and its impacts need to be addressed right away. Although some see that as a diversion from addressing causes, it is more likely to help us to do that, because seeing serious adaptation measures helps convince people that the issue is being taken seriously now, rather than just seen as something that may happen in the distant future.
• This is reinforced by the long list of impacts already being attributed to climate change (pages 32, 33 & 34 in the report’s Summary). What is striking about the list is how varied it is. That is why it was always a mistake to call all this “global warming”. Although the rise in average global temperature is a key factor, the consequences of climate change – including floods, droughts, wildfires, sea level rise, declines in fish stocks and wheat production, even periods of exceptional cold – indicate a complex and wide-ranging phenomenon, not a simple one just about temperature.
• The impacts on different species are varied too, largely depending on how fast they can move. Phytoplankton species in the oceans are moving fast (at a rate of 40 km a year, according to the chart on page 36), whilst at the other end of the scale, the speed of movement of trees and herbaceous plants is dead slow, making them more vulnerable.
• The report also gives some space to another of the nine planetary boundaries – ocean acidification – not because it is a consequence of climate change, but because it is a second consequence of carbon emissions and the rising concentration of carbon in the atmosphere and oceans. This might perhaps prefigure the addition of ocean acidification provisions to international agreements on climate change, since it lacks a major agreement of its own.
Do I have any criticism of the report?
Unlike some people, I am not prepared to argue with the consensus of the world’s climate scientists. I don’t imagine I know more than they do about climate science. However, climate science is not everything, and where I think the report has difficulties is where it brings in, or obviously needs to bring in, other factors. There really are no impacts of climate change on its own, because it never is on its own.
To really see its consequences, we need to analyse how it interacts with other factors. At various points, the report refers to that (what it calls “multiple stressors”), but in my view it does not tackle this question adequately.
The problem about doing that, of course, is that the issues become both intensely political – as the report says, it is harder for the poor and marginalised to adapt to climate change than for the rich and well-resourced to do so – and of course, more complicated. Such a study would need to consider, for example, the economics of land use shifts and the prospects for fighting, taming, or nicely persuading the giant fossil fuel companies to change their ways.
This takes us a long way beyond the mandate of Working Group Two, and beyond what the natural science community is comfortable with – and out into the politics of the run-up to next year’s major climate conference in Paris.
Victor is a Director of PBI and Visiting Professor, Global Sustainability Institute, Anglia Ruskin University: email@example.com