Is 1,5°C enough? [climate deal]

Jędrzej Brzeziński: According to the Nobel Price winning IPCC (Intergovernmental Panel on Climate Change) our future to be – or not to be – lies somewhere within the range of 1,5 – 4,8+°C by 2100. Could you please explain what these values mean and why that range is so important?

Sebastien Kaye: The difference between 1,5 and 4,5°C seems tiny in terms of daily experience, but the same difference between average temperatures in the atmosphere would be unbelievably drastic. Already the difference between 1,5 and 2°C is very big, in terms of masses of people being affected. 4+°C will mean the end of human life as we know it. 4°C would eventually engender a rise in sea levels up to 9 meters. The IPCC gives only a note about 25 – 80 cm by 2100, but a new study from Hansen et al. takes feedback amplifications into account and predicts 5-9 meters. So for example Shanghai – a city which has over 24 million inhabitants – will be almost entirely submerged. Shanghai is just one of the thousands of cities which is situated in a coastal area. In fact over 1/3 of humanity lives in coastal regions. And of course those cities were not built with the correct infrastructure to account for such drastic sea level rises.

At the moment, scientists say we have produced an average of 0,85°C of global rise in temperature.

That was correct in 2010. And 2015 was already 1°C warmer than before the pre-industrial level. Science shows that we’ve already emitted so much greenhouse gas that we will reach 1,5°C anyway, it’s just a matter of time. In fact in order to stop 1.5°C from happening (which would save a lot of Pacific island states) we would have to stop emitting 100% of global greenhouse gas emissions now. We need to remember that there is a delay in the amount of CO2 in the atmosphere and consequent global warming. This might seem bizarre since politicians are still talking about 1.5°C as a realistic goal. The scientific reality – the laws of nature and statistical probability – are off the table at COP21, replaced by inadequate political pledges and all too often optimistic possibilities which end up being unrealistic. To understand how the atmosphere warms up relative to how much we emit we need to look at how many molecules of CO2 there are per 1 million molecules of dry air (ppm). We are now just over 400 ppm, up one third from pre-industrial levels, and higher than anything experienced before by humans. The mean average of this growth for the last 10 years has been 2.06 ppm per year. That would mean that at constant emissions of 450 pm, 2°C will be reached in about 24 years!

We learn more and more, but we don’t seem to really know more.

That’s right, unfortunately. There is another even bigger problem with the language used by politicians and policy makers in relation to that. They say: we are going to reduce our emission rates by – let’s say 30 % – in accordance with 1995 levels. But what does this mean? When you decipher it and do the maths behind it, it turns out that what it implies is basically nothing. It just means that there will be a tiny decrease in the increase of emissions. So politicians aren’t even talking about stabilizing greenhouse gas emissions – let alone reducing them – when they make these types of announcements. They use the language as a smokescreen behind which the significant change that is necessary does not happen. So what the scientists have concluded is that to limit the warming to 2°C requires limiting emissions to 790 GtCO2 from today onwards. To keep track of this, we came up with the carbon giga-ton-clock (Giga Clock for short). The Giga Clock is an ever decreasing number, calculating the amount of carbon we have left to emit until we reach 2°C. You can think of it as a bit of a “doomsday clock”. Basically, we reach 2°C when 790 gigatons of CO2 is released into the atmosphere. I’m part of a student lobby group which has been actively lobbying to introduce into political language this quantifiable and measurable framework to monitor our progress in stabilizing CO2 concentration in the atmosphere. The carbon Giga Clock is a concrete way of providing a solution to the problem of abstract, artificial, and misleading percentage calculations currently used by politicians. Instead of speaking about the real reductions in actual masses of CO2 being produced, political jargon continues to further confuse people on what is already a complicated issue.

But if this is only a problem of the terminology used, surely this can be translated into percentage-values, right?

Yes, but the emission reductions proposed for the COP21 are drastically insufficient! I have read in popular newspapers about the need to increase Intended Nationally Determined Contributions (INDCs) by 200% in order to limit atmospheric temperatures to below 2°C. This is simply false information based on incorrect mathematics! With the Homo Sapiens Foundation we have done the calculations and the results are shocking. In order to limit atmospheric temperatures to below the 2°C threshold we must increase the INDCs by 1100%. This information has been verified by scientists in the IPCC and the WMO (World Meteorological Organisation) but can simply be found nowhere in the public eye, the media or on the tables at the COP21 conference. In fact, I don’t even know where the 200 % number was taken from. The worst is that people believe it!

 So, considering the fact the 1.5°C is already dangerous, the 2°C, which is at stake in the  negotiations, seems very unsatisfactory.

2°C of temperature rise would displace around 300 million people Click to Tweet

Yes, it is unsatisfactory. What is important to remember is that scientists already wanted 1°C of atmospheric temperatures to be the limit. Not 1.5°C, not 2°C. I was at a lecture on sea level rise last week and Dr Benjamin Strauss – an expert of rising see levels – said that already 2°C would displace around 300 million people as a consequence of sea level rise. Nevertheless, 2°C is still a realistic option – and a much better alternative to what comes after it – but politicians must act now. The Homo Sapiens Foundation have made the scientific calculations and what is needed – in order to limit atmospheric temperatures to below 2°C – is to reduce global CO2 emissions by 0.4% every month, starting now, until 2035, increasing with inaction. This is how 2°C would still be a feasible goal, but it would require a radical change of attitude on behalf of policy makers.

 300 million?!

Yes, and that’s just sea levels, but climate change is much more than that. To understand what climate change really is – we need to understand first what the climate equilibrium is. Climate equilibrium is when the Earth receives the same amount of energy from the sun as it emits into space. This equilibrium has now been disrupted by anthropogenic greenhouse gas emissions resulting in the Earth receiving more energy than it can send out. This natural “balance” is very fragile and man-made interference is affecting it. 2°C is extremely important here, because it is a threshold for many natural disasters, which are likely to happen once you pass it. The scary part is that those potential catastrophes tend to propel one another like a viscous circle turning the Earth into a giant Pandora’s box. Let’s take the common example which everyone knows; the glaciers in the North. They do not only store huge amounts of water in solid form, but also reflect the suns energy back into space. Another effect of global warming after 2°C will be the melting of the permafrost (permafrost is very old ice found in northern regions of the world like Siberia). These old ice sheets trap masses of methane underneath them, which is fifty times more harmful to the atmosphere than carbon dioxide! Methane doesn’t stay in the atmosphere as long as CO2, but there might not be time left for this difference to play any role. This amount of global warming will cause the oceans, which absorb large amounts of greenhouse gases, to become more acidic which would in turn, cause mass extinction of marine life. This causes another feedback loop: extinction of fish causes a huge gap in the food chain, disastrous for the whole of biodiversity and hence, for the global ecosystem. This would of course have disastrous effects on human life, economic stability, immigration, food supply, the list goes on… On land there won’t be a shortage of problems either, with phenomena like desertification, drought, more severe weather such as hurricanes, growth in the numbers of people infected by diseases like malaria (because the environmental conditions for malaria-carrying mosquitoes will become more frequent) as well as and many other problems, some of which we cannot foresee. So this big and very dangerous interconnectedness will start to overlap and develop.

Are politicians really not aware of this?

An international UN treaty, called the United Nations Framework Convention on Climate Change (UNFCCC), around which the COPs are organized, contains their objective stated in article 2. That objective is clear: to stabilize greenhouse gas concentrations at a safe level. The fact is that throughout its 20-year history, the UNFCCC has failed to reach its objective. From COP1 in Berlin 1995 to COP20 in Peru last year, there has only been an objective failure, no “stabilisation” – only destabilisation. This means that despite all the work done around UNFCCC and COP meetings we are still increasing our carbon emissions to a dangerous level. The negotiating outcome does not correspond to the emissions outcome. Greenhouse gas concentrations have gone up from 360ppm (1995) to +400ppm (2015). Let’s say it once again: 2 degrees is not a safe level and we are apparently going to go above the 2 degrees. So it’s this sense of urgency that fuels me to make this information public. Our objective here is to give people the right and means to know. Because if more people knew this sort of information then we wouldn’t let politicians screw us like this. The situation does not have an immediate effect on us here and now, however you can already see it in some areas of the world, but that is what is going to happen. We have the privilege, however dubious, to see the change, but our kids will be already born into a completely different world.

A common response is that in the long time that it will take for the climate to warm up mankind will surely invent a method to undo its negative effects. What do you think about that?

So that almost naive reliance on science as an unfailing means to provide the solution to the problem in the future effectively proves to be the reversal of just the same type of common ignorance and denial of seeing what science actually says. The top scientists who’ve dedicated their lives to researching global warming say that we just don’t have a viable option to deal with taking the necessary amounts of CO2 out of the atmosphere to stay at a safe level of global warming. The only means of stopping climate change is to reduce our greenhouse gas emissions before it is too late!

Can we identify the countries that are most responsible for our current climate situation?

We can’t forget that we should be talking about emissions per person. Here is how to illustrate what I mean: let’s say that the speed limit to reducing all our emissions to 2°C is 100km, that is to say, if we drive slower than 100km an hour we don’t reach 2°C and the contrary happens if we go over the limit. In this case, China is going at 400km/h. Which is already a lot, but Europe is going at 800km/h and the USA is going at 1200km/h! So if everyone was like the US we would have reached a disastrous level of global warming a long time ago. All too often in the media we see people pointing fingers at China, you hear “China is the country which emits the most! They are to blame!” But let us not forget, China has also got the largest population in the world. If you divide the emissions equally by the population you will find that the developed world has much more blood on its hands than it would like to think. So yes, China pollutes the most, and that is not questionable. But if we think about it in terms of equality – everyone after all should have the right to pollute the same amount – then we have to admit that we, the citizens of western developed countries are by far worse.

It all sounds very depressing indeed. Do you see any positive aspects of the COP21 though?

A minor success is that François Holland managed to gather around 140 heads of state from countries around the world and each of them clearly said more or less the same thing: “global warming is a problem and we need to do something about it.” So there is a general consensus for there to be international change. Of course some countries want governments to reduce emissions more than others, specifically the representatives of Pacific island states, whose citizens will soon have to emigrate if we continue with the current trend. Prime ministers or presidents of those countries will have to ask other countries to take in people from their nation state, which is absolutely unprecedented and pretty tragic too. Can you imagine a prime minister of a country calling up another head of state to ask if the latter will host his citizens? But Pacific island states are not the only case here. Major flooding will also happen in countries like the Netherlands.

The Netherlands is said to be a country with such experience and developed infrastructure for flood protection that they are well prepared to survive the sea level rise.

That’s what is being said indeed, and when you talk to Dutch people they are often not very bothered about it and they believe they will cope with it with a surprisingly relaxed attitude. It is probably true that they will be able to survive it for some time, they have already invested in flood prevention systems. They could hypothetically build a wall to block out the sea level rise. But who would really like to live at the bottom of a bowl which is so deep? Imagine someone detonates a bomb on that wall… This becomes very problematic already with a 1-meter rise, which is still an optimistic prognosis.

What is the pessimistic one?

A pessimistic one would be a scenario in which we continue, on current trends, to increase our CO2 emissions. This would eventually mean an atmospheric temperature rise of above 4°C, which hypothetically would continue well past 4°C. Of course, the warmer it gets, the more difficult it is to stop. We do not ask ourselves “if” we should stop digging for fossil fuels – we only ask when, and even that question is in fact a rhetorical one. The answer is clear: the time is now. If you were to say that there are no black or white situations, this would be the exception. The scenario to avoid: 4°C of atmospheric temperature rise which would in the long run cause 10 meters of sea level rise. Scientists estimate that per each centimetre of the first metre of such a rise, one million people would need to be displaced. If this tendency would hold true with the next meters, +4°C would cause up to 1 billion people to immigrate! Now think of all of the fragile ecosystems people rely on for food, materials, and other domains – they simply won’t exist anymore. Clean water will become a rare commodity. At the beginning of the 21st century we’ve seen wars take place over resources such as oil, but think about the possibility of water wars, it is really like a “Mad Max” scenario. So this is what we are trying to avoid but regrettably we are not doing enough.


Sebastien Kaye – he has worked with a grassroots environmental student lobby group for the past two years. Since then, he worked with the Homo Sapiens Foundation who do – amongst other things – scientific research in the field of global warming and mass resource depletion. The information Foundation produces is peer reviewed by other leading scientists in this field.

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