tisdag 21 januari 2020

57. Greta in Davos 2020

One year ago I came to Davos and told you that our house is on fire. I said I wanted you to panic. I’ve been warned that telling people to panic about the climate crisis is a very dangerous thing to do. But don’t worry. It’s fine. Trust me, I’ve done this before and I assure you it doesn’t lead to anything.

And for the record, when we children tell you to panic we’re not telling you to go on like before.

We’re not telling you to rely on technologies that don’t even exist today at scale and that science says perhaps never will. We are not telling you to keep talking about reaching “net zero emissions” or “carbon neutrality” by cheating and fiddling around with numbers.

We are not telling you to “offset your emissions” by just paying someone else to plant trees in places like Africa while at the same time forests like the Amazon are being slaughtered at an infinitely higher rate.

Planting trees is good, of course, but it’s nowhere near enough of what needs to be done, and it cannot replace real mitigation or rewilding nature.

Let’s be clear. We don’t need a “low carbon economy.” We don’t need to “lower emissions.” Our emissions have to stop. And until we have the technologies that at scale can put our emissions to minus then we must forget about net zero — we need real zero.

Because distant net zero emission targets will mean absolutely nothing if we just continue to ignore the carbon dioxide budget — which applies for today, not distant future dates. If high emissions continue like now even for a few years, that remaining budget will soon be completely used up.

The fact that the U.S.A. is leaving the Paris accord seems to outrage and worry everyone, and it should.

But the fact that we’re all about to fail the commitments you signed up for in the Paris Agreement doesn’t seem to bother the people in power even the least.

Any plan or policy of yours that doesn’t include radical emission cuts at the source starting today is completely insufficient for meeting the 1.5-degree or well-below-2-degrees commitments of the Paris Agreement.

And again — this is not about right or left. We couldn’t care less about your party politics.

From a sustainability perspective, the right, the left as well as the center have all failed. No political ideology or economic structure has been able to tackle the climate and environmental emergency and create a cohesive and sustainable world. Because, in case you haven’t noticed, that world is currently on fire.

You say children shouldn’t worry. You say: “Just leave this to us. We will fix this, we promise we won’t let you down.”

And then — nothing. Silence. Or something worse than silence. Empty words and promises which give the impression that sufficient action is being taken.

All the solutions are obviously not available within today’s societies. Nor do we have the time to wait for new technological solutions to become available to start drastically reducing our emissions.

So of course the transition isn’t going to be easy. It will be hard. And unless we start facing this now together, with all cards on the table, we won’t be able to solve this in time.

In the days running up to the 50th anniversary of the World Economic Forum, I joined a group of climate activists who are demanding that you, the world’s most influential business and political leaders, begin to take the action needed.

We demand that at this year’s World Economic Forum participants from all companies, banks, institutions and governments:

Immediately halt all investments in fossil fuel exploration and extraction.

Immediately end all fossil fuel subsidies.

And immediately and completely divest from fossil fuels.

We don’t want these things done by 2050, 2030 or even 2021, we want this done now.

It may seem like we’re asking for a lot. And you will of course say that we are naïve. But this is just the very minimum amount of effort that is needed to start the rapid sustainable transition.

So either you do this or you’re going to have to explain to your children why you are giving up on the 1.5-degree target.

Giving up without even trying.

Well I’m here to tell you that unlike you, my generation will not give up without a fight.

The facts are clear, but they’re still too uncomfortable for you to address.

You just leave it because you think it’s too depressing and people will give up. But people will not give up. You’re the ones who are giving up.

Last week I met with coal miners in Poland who lost their jobs because their mine was closed. And even they had not given up. On the contrary, they seem to understand the fact that we need to change more than you do.

I wonder, what will you tell your children was the reason to fail and leave them facing the climate chaos you knowingly brought upon them? The 1.5-degree target? That it seemed so bad for the economy that we decided to resign the idea of securing future living conditions without even trying?

Our house is still on fire. Your inaction is fueling the flames by the hour. We are still telling you to panic, and to act as if you loved your children above all else.

onsdag 23 oktober 2019

56. Unite behind science

HISTORY
In the middle of 1890's the scientist Svante Arrhenius proposed that the use of fossil fuel would change the climate. Carbon dioxide and some other greenhouse gases works like clothing for earth. The sun is heating up earth surface and the greenhouse gases stop some of the heat radiation to vanish back in space. More clothing make the surface warmer.

At that time science had discovered that earth previously had several periodical times of extended polar glaciation. A great deal of northern Europe and northern America had some 20 thousand years ago been covered by ice of great depth. And seemingly, the start of the next glaciation was rather close in time, perhaps in 10 thousand years. Arrhenius thought that the use of coal and petrol most probably would prohibit the next glaciation.


Fossil fuel comes from underground rests of ancient plants and animals. The carbon of the fuel had once been a part of a biosphere with a completely different climate. For hundreds of million years carbon has vanished from the biosphere, decreasing the rate of atmospheric carbon dioxide and decreasing the global mean temperature. 


About one million years ago the era of periodic glaciations started with about one glaciation in hundred thousand years. When the sea become colder it resolves carbon dioxide better and when it get warmer it release carbon dioxid to the atmosphere. As in the case with sparkling water. An idea of Arrhenius was that the pendling migration of carbon dioxide between sea and atmosphere caused the periodic glaciations. When the atmospheric carbon dioxide was minimal at about 180 ppm, the temperature was as lowest. Without greenhouse gases earth would be totally covered with ice.




Since the fossil process naturally goes in one direction, it would be less and less carbon dioxide in the biosphere. So in a way the fossil fuel is an asset not only for energy but also for climate regulation. At the time of Arrhenius the use of fossil fuels was just a small fraction of what we use today. Arrhenius supposed that the emission of carbon dioxide wouldn't extend today emission in thousand years. He couldn't then foresee the rapid evolution of modern society. Slower emissions of carbon dioxide would have been possible to manage without the risk of global disaster.


CALCULATIONS

Arrhenius deduced a law for the relation between the content of carbon dioxide and the global warming from Stefan-Boltzmanns law of thermal equilibrium:

a certain increase of temperature correspond to a doubling of the content of carbon dioxid i  the atmosphere. 


Or as a formula: T2-T1=aλ*ln(C2/C1), a≈5.35 and λ is a value called climate sensitivity, estimated to be λ≈0.8.


Normally the mean temperature and the mean content from 1850-1900 is used as T1 and C1 and C1≈290 ppm. Today content of CO2: C2≈410 ppm, which gives


T2-T1≈ 5.35*0.8*ln(410/290)≈5.35*0.8*0.35≈1.5 °C


Due to IPCC T2-T1=1.0±0.2 °C only, but Arrhenius formula  assume that earth surface is a rigid body, while 70 % of the surface is actually sea water. The sea is accumulating about 90 % of the energy from the insolation and deep sea levels are warming up. At land the insolation is only warming some few decimeters down. Therefore the surface of the sea is cooler than the surface of land. The result of the formula should be multiplied with 2/3 to correspond with the real values from 70 % sea surface globe.


Also due to IPCC the best scenario (Paris agreement) for year 2100 is about 550 ppm and the worst scenario (go on like now) is about 900 ppm. (See diagram above). Calculus as above gives:


Best case:  T2-T1≈5.35*0.8*ln(550/290)*2/3≈1.8 °C.

Worst case: T2-T1≈5.35*0.8*ln(900/290)*2/3≈3.25 °C.

MODERN VIEW

Milutin Milaković hypothesized in 1920 that variations in eccentricity, axial tilt, and precession of the Earth's orbit resulted in cyclical variation in the solar radiation reaching the Earth, and that this orbital forcing caused the periodical glaciations.



The surface temperature on earth depends on the heating effect from the sun (W/m2) and the isolating effect from the greenhouse gases. In the last 5 thousand years the heating effect from the sun had decreased due to the Milankovitch cycles. Unless there are big enough unknown effects, the latest sequel of global warming must be caused by the isolation effects of greenhouse gases. 


Since there is an abnorm contribution of extra carbon dioxide from the use of fossil fuel, there must be a warming effect from that. And since the warming has accelerated extra the last 40-50 years as the emission has increased exponentially, there are no serious reasons to deny the conclusion from science: human being cause a global warming of 0.2 °C per decade.








Exxon Mobile 1982 predicted today levels



LINKS ABOUT GLOBAL WARMING

NASA on global change
National Geographic on global change
SMHI on global warming
Scientific American on global warming
Intergovernmental Panel on Climate Change
Wikipedia on global warming
History of climate change science Wikipedia