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Skip to 0 minutes and 8 secondsWhat we see is we see the carbon dioxide emissions have gone up over time. This is from 1990 out to 2050. And we know we have a carbon budget of total carbon dioxide that we can put in the atmosphere for 2 degrees centigrade. And that carbon budget relates to this area here underneath the pathway, the emissions pathway that we're currently heading up. And if we keep on going, we keep going up and up. But we need to come down if we're going to hold to 2 degrees centigrade.

Skip to 0 minutes and 33 secondsAnd if we fail to do anything in the near term-- and of course, that's what most of us are doing, we are failing to really address climate change seriously-- then our emissions at the global level will continue to rise. And because we have a set carbon budget, they continue to rise, then we will have to have much more stringent mitigation later. So what we put in the atmosphere now has to be taken out later on. We have to reduce our emissions later on. That means the mitigation rates will be much higher. So we'll have to make... Even already it's going to be very difficult for us to reduce our emissions in line with 2 degree centigrade.

Skip to 1 minute and 5 secondsBut if we don't do something now, it becomes much more difficult. And very soon, we will completely lose any opportunity for 2 degrees. Before Paris, we were aiming this sort of pathway. We were aiming to a 4 to 6 degree C temperature rise, which would have, as the International Energy Agency has said, devastating consequences for the planet. This is effectively a different planet Does not look like the world that we live in if we ended up going here. And this would be within this century, within the lives of our children today. The pledges take us to about a 3 to 4 degree C temperature rise. But we have committed to 2 degrees centigrade.

Skip to 1 minute and 40 secondsAnd you can see here there's a big difference between the pathways that we would need to follow. My argument has been, for a long time, that we need to have very rapid and deep cuts in energy demand if we are going to be able to stay within the 2 degrees C, or indeed the 1.5 degrees C, but I'll come back to that later. Thresholds. Now, we need the low carbon energy supply or 0 carbon energy supply, renewables, possibly carbon capture and storage, or it could be nuclear as well. These are all very low carbon forms of energy. We need those as well, but they cannot be built fast enough.

Skip to 2 minutes and 14 secondsSo in the short term, we need to reduce our energy demand to keep within the 2 C threshold. And I'll come back to that in a few minutes. But this is a global picture. And we have signed up to commit to this 2 degree C or 1.5 degree C threshold on the basis of equity. In other words, the poorer parts of the world have longer to do something about this. So let's go back to the carbon budget. So let's quickly talk about 1.5 degree centigrade.

Skip to 2 minutes and 39 secondsIn the next 5 to 8 years, that's before we get to review the pledges from the different countries of the world, we would have put so much carbon dioxide in the atmosphere that no longer would it be possible to hold to the 1.5 degree C temperature rise. So the Paris agreement had enshrined within it, its own demise in terms of 1.5 degrees C. The only way around that is to assume that these Doctor Strangelove technologies will work in many decades from today and suck carbon dioxide from the atmosphere, which is a very dangerous assumption, in particular, when it was not made explicit within the agreement.

Skip to 3 minutes and 13 secondsSo 1.5 degree C is no longer possible because we're going to put too much carbon dioxide in the atmosphere over the next few years. A good chance of 2 degrees C, that is also gone. So we no longer have a good chance of 2 degrees C. Even a 50-50 chance of 2 degrees centigrade would require us to think of climate change like we were at a war-type footing. And nowhere around the globe is anyone that serious about climate change, no country is, really no individuals are prepared to see it that seriously yet, even though the science points us very clearly in that direction. So the 50% chance is also gone.

Skip to 3 minutes and 46 secondsSo we now are left with only an outside chance of holding to 2 degrees centigrade. And as I said before, that would already mean many people will die around the planet. So this is not a safe threshold, but it looks to me now the best we can hope for is to aim for 2 degrees C. But even that will be hugely challenging. So let's go back to the carbon budgets again. We have a certain carbon budget for how much carbon we can put in the atmosphere for 2 degrees centigrade for just an outside chance of 2 degrees. And we can make some estimates about how much emissions the poor parts of the world are putting in the atmosphere.

Skip to 4 minutes and 20 secondsSo let's imagine the poor parts of the world, that includes China and India, the continent of Africa, some South and Central American countries, and a few other countries elsewhere. Let's imagine they could peak their emissions. Remember, the emissions of carbon dioxide reach a peak by 2025 and then start coming down. Now, that's about 5 years earlier than China says it's possible for China and 15 years or so earlier than India says it's possible for India. But still talking with other colleagues and some Chinese colleagues as well, they think that it is viable still to peak in 2025 if we're very serious about climate change. After that, we start to reduce our emissions.

Skip to 4 minutes and 53 secondsAnd let's imagine that by 2035, the poor part of the world are able to reduce their emissions at 10% every single year. That's about two to three times faster than most economists would tell us is possible with economic growth. So that is a huge request. That means that by 2050, the poor parts of the world have no more carbon dioxide coming from their energy system, not just their electricity, their planes, their ships, their fridges, their cars, everything. So we can work out the carbon budget for that. We have a carbon budget for 2 degrees C. And we can say what's left for the wealthy parts of the world, the UK, USA, the EU, Australia, Japan, and so forth.

Skip to 5 minutes and 34 secondsAnd basically across the board, wealthier people around the world, wealthier nations, would have to reduce their emissions at about 10% every single year. And you just think what that means. That means by 2020, we would have to have reductions of about 50%. By mid 2020, by about 75%. By 2030, about a 90% reduction. And by 2035, at the outside, we'd have to remove all carbon from our energy system within 20 years really of today. That's a huge request. But again, I think it's just about viable. And this gives us only then an outside chance of 2 degrees centigrade. So this is an enormous challenge beyond anything that is currently being countenanced by any country.

Skip to 6 minutes and 14 secondsThe EU has put a pledge into the Paris agreement for only a 40% reduction, less than half of what would be necessary. So no country is doing what's required at the moment, anyway near for 2 degrees centigrade. So the rhetoric is very loud. And we hear this all the time, but the actual action is very weak indeed.

Carbon budgets and emission pathways

In this video, visiting Zennström climate change leadership professor Kevin Anderson introduces the concept of carbon budgets and why it is important for climate leadership and action.

Since carbon dioxide stays in the atmosphere for a long time, we only have a certain carbon budget of cumulative carbon emissions that can be emitted before a certain temperature threshold is met.

We’re currently heading up and […] we need to come down if we are going to hold to 2°C. If we fail to do anything in the near term, and of course that’s what most of us are doing […] then emissions at the global level will continue to rise. And because we have a set carbon budget, if they continue to rise then we will have to have much more stringent mitigation later.

This means that we need to focus just as much on current emissions as on long-term targets:

So it’s been very misleading these discussions about [emissions targets for] 2050, what we do today, and tomorrow, and the day after is really important. That is why actually, given that we’ve failed the last 25 years that is also very important because that carbon dioxide is in the atmosphere now for a hundred to ten thousand years and its changing the climate as we speak.

Since the carbon budgets are so tight, time is short if we are going to be able to meet the 2°C target:

Already, it will be extremely difficult for us to reduce our emissions in line with 2°C, but if don’t do something now it will be much more difficult. And very soon we will completely lose any opportunity for 2°C.

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This video is from the free online course:

Climate Change Leadership

Uppsala University

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