IPCC report gloomier outlook on climate

As wildfires wreak havoc across Greece and California, off the back of shock floods in parts of Europe and a heatwave across the western half of North America that saw temperatures touch 50 degrees Celsius in Canada, the message this week from the IPCC - the intergovernmental panel on climate change - was chilling. Imperial College’s Joeri Rogelj is one of the authors of the new report that spawned those headlines. Chris Smith wanted to know what’s changed since the last such update was published, in 2015, and how reports like this might or might not be able to help stimulate action to combat what many regard now as a full blown climate crisis…

Joeri - For the first time, the intergovernmental panel on climate change now states unequivocally that our human actions are responsible for the change that we are seeing around us. The report also states that to stop global warming, we have to bring down our global emissions to zero. These two pieces of information really tell us where we are today, but also what we should be doing.

Chris - It comes across as quite a sort of slap on the wrist slash finger waggling, 'we told you so' and now we're even more sure this outing of the report, the message hasn't greatly changed, but the tone of the language and the certainty certainly has.

Joeri - Well, these reports from the IPCC, we publish them every five to seven years. So, as climate change has been progressing, the report can say things with greater urgency, can show greater impact. and so on. At the same time, the report also has made great improvements in what we scientifically understand and attributing what we see to human activity. It's one of those great advances of this report.

Chris - Words like unequivocal are really very powerful. So, what has changed in the last five years that means that you can now say pretty much unequivocally, this is because of what we're doing. Whereas five years ago, there was a lot more uncertainty around the word.

Joeri - The reason for this is really twofold. First of all, we have seen more climate change, more warming. And so the signal of what we're seeing is coming out of the noise, unprecedented extreme events that could not have happened if not for climate change. The second reason is that methods and computer power have increased a lot, and these are necessary for the calculations to be able to make these statements.

Chris - And when we say IPC, it's often not reported as to exactly what the intergovernmental panel on climate change is. Who's on that panel and how these reports get put together. So, can you explain it for me?

Joeri - I'm an author for the IPCC, but the IFCC are 195 countries, all the countries, pretty much of the United nations and this one at 95 countries, they come together, they commission reports and then the scientific community, we are producing those reports, following a very rigorous, transparent and open process that runs over many years. For example, in this report, we prepared roughly three years for it. We answered more than 70,000 review comments. The report then gets signed off sentence by sentence by those 195 countries, which makes these reports very powerful in the political arena.

Chris - Yes indeed, because obviously having buy-in from all those different member countries means that it's relevant to a global community, but is not part of the problem, there are some countries that are accounting for a disproportionate amount of emission and the report doesn't point fingers. It's very smooth in its language around human activity.

Joeri - Yeah, that is one aspect of IPCC reports. IPCC reports have to be policy relevant, but can't be policy prescriptive. That means that there is very little finger pointing going on. For reports that are more pointing fingers there are other organisations, including NGOs that do a much better job at this.

Chris - But there is some sort of facility being made for legal action now isn't there around this so that countries can be brought to the table and their behaviour, in terms of emissions and so on, can actually attract some legislative manipulation?

Joeri - Absolutely. There are a few avenues where this can happen. First and foremost actually, the report will be feeding into political discussions. For example, in the context of the climate summit at the end of this year in Glasgow, it's not legal action, but it's definitely diplomatic action of countries putting pressure on each other. But then indeed, as you say, this report really provides a very good basis for legal action. First, we can now attribute changes that we see around us to human activity. So, we can really say also in a court human activities are responsible for much of the damage that we are seeing. On the other hand, as the report also shows what needs to be done to limit warming to safe levels, this also provides a really interesting puzzle piece for legal action.

Chris - When you say how much carbon dioxide we can still emit, that answer isn't very much though is it? We don't have very long before we really have run out of runway.

Joeri - Yes indeed. If we want to limit our warming to levels that are considered safe. That is kind of the iconic 1.5 degrees of global warming, the carbon budget, that we can still admit is very small. I'm now going to throw around a few numbers, 500 billion tons of CO2, and putting that in context on an annual basis, we admit around 40 billion tons. So, that means in slightly more than 10 years, this budget would be used up if we don't decrease our emissions from today.

Chris - So, are you optimistic or pessimistic?

Joeri - I'm a typical optimist. At the same time I'm a realist. While I know that it is necessary, while I know that we can do it, and for example, the great efforts that have been done during the COVID pandemic show that if the need is there and if the will is there, change can be implemented very rapidly. But I'm also a realist in my own research, I research where emissions are heading based on the promises that governments have made today. And that really shows that we are not on track to limit global warming to safe levels at all. By mid century we would be well beyond all the global goals that we have set ourselves. So, I also see that side of the coin.