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This article is republished from The Conversation under a Creative Commons license. Read the original article.
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The COP28 climate summit in Dubai has adjourned. The result is “The UAE consensus” on fossil fuels.

This text, agreed upon by delegates from nearly 200 countries, calls for the world to move “away from fossil fuels in energy systems in a just, orderly and equitable manner”. Stronger demands to “phase out” fossil fuels were ultimately unsuccessful.

The agreement also acknowledges the need to phase down “unabated” coal burning and transition towards energy systems consistent with net zero emissions by 2050, while accelerating action in “the critical decade” of the 2020s.

As engineers and scientists who research the necessary changes to pull off this energy system transition, we believe this agreement falls short in addressing the use of fossil fuels at the heart of the climate crisis.

Such an approach is inconsistent with the scientific consensus on the urgency of drastically reducing fossil fuel consumption to limit global warming to 1.5°C.


‘Abated’ v ‘unabated’

The combustion of coal, oil and gas accounts for 75% of all global warming to date – and 90% of CO₂ emissions.

So what does the text actually ask countries to do with these fuels – and what loopholes might they exploit to continue using them well into the future?

Those countries advocating for the ongoing use of fossil fuels made every effort to add the term “unabated” whenever a fossil fuel phase-down or phase-out was proposed during negotiations.

“Abatement” in this context typically means using capture capture and storage technology to stop CO₂ emissions from engines and furnaces reaching the atmosphere.

However, there is no clear definition of what abatement would entail in the text. This ambiguity allows for a broad and and easily abused interpretation of what constitutes “abated” fossil fuel use.

Will capturing 30% or 60% of CO₂ emissions from burning a quantity of coal, oil or gas be sufficient? Or will fossil fuel use only be considered “abated” if 90% or more of these emissions are captured and stored permanently along with low leakage of “fugitive” emissions of the potent greenhouse gas methane, which can escape from oil and gas infrastructure?

This is important. Despite the agreement supposedly honouring “the science” on climate change, low capture rates with high residual and fugitive emissions are inconsistent with what research has shown is necessary to limit global warming to the internationally agreed guardrails of 1.5°C and 2°C above pre-industrial temperatures.

In a 2022 report, the Intergovernmental Panel on Climate Change (IPCC) indicated that almost all coal emissions and 33%-66% of natural gas emissions must be captured to be compatible with the 2015 Paris agreement.

That’s assuming that the world will have substantial means of sucking carbon (at least several billion tonnes a year) from the air in future decades. If these miracle machines fail to materialise, our research indicates that carbon capture would need to be near total on all fuels.

The fact that the distinction between “abated” and “unabated” fossil fuels has not been clarified is a missed opportunity to ensure the effectiveness of the Dubai agreement. This lack of clarity can prolong fossil fuel dependence under the guise of “abated” usage.

This would cause wider harm to the transition by allowing continued investment in fossil fuel infrastructure – new coal plants, for instance, as long as some of the carbon they emit is captured (abated) – thereby diverting resources from more sustainable power sources. This could hobble COP28’s other goal: to triple renewable energy capacity by 2030.

By not explicitly defining these terms, COP28 missed the chance to set a firm, scientifically-backed benchmark for future fossil fuel use.

The coming age of carbon dioxide removal

Since the world is increasingly likely to overshoot the temperature goals of the Paris agreement, we must actively remove more CO₂ from the atmosphere – with reforestation and direct air capture (DAC), among other methods – than is emitted in future.

Some carbon removal technologies, such as DAC, are very early in their development and scaling them up to remove the necessary quantity of CO₂ will be difficult. And this effort should not detract from the urgent need to reduce emissions in the first place. This balanced approach is vital to not only halt but reverse the trajectory of warming, aligning with the ambitious goals of the Paris agreement.

There has only really been one unambiguously successful UN climate summit: Paris 2015, when negotiations for a top-down agreement were ended and the era of collectively and voluntarily raising emissions cuts began.

A common commitment to “phase down and then out” clearly defined unabated fossil fuels was not reached at COP28, but it came close with many parties strongly in favour of it. It would not be surprising if coalitions of like-minded governments proceed with climate clubs to implement it.

Mass fish deaths due to Pacific Norrthwest marine heatwave

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What he said…

“Our wise and noble leaders have just concluded the 27th annual global climate conference known as COP27. They all seem jolly pleased with what they’d all decided to achieve including really very sincere commitment to work super-duper hard to put in place policy that would definitely address the idea of thinking about doing things that might contribute towards the possibility of reducing greenhouse gas emissions with the aim of maybe limiting global temperatures to only 1.5 degrees Celsius above preindustrial levels. Then there were the 636 lobbyists—I mean delegates at COP27—representing the fossil fuel industry who reassured us all that increasing oil and gas exploration was actually an extremely important part of the transition toward achieving the 1.5 degrees Celsius target.”

COP26 logo

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The carbon budget: a moving target that politicians just moved beyond reach.

Fig. 1. This live feed from the Mercator Institute is, by default, set to show how much time we have left before the CO2 budget to stay under 2°C is no longer possible. The CO2 budget is in tonnes. Currently (18 March 2022), it’s 1,060Gt (Gt = 1 billion tonnes). At the present rate of emissions, this will run out around April 2047.
 
However, if we want the planet to remain habitable for most (but not all) people, and accept losing entire ecosystems like the Great Barrier Reef, we need to keep the average temperature rise under 1.5°C.

Click the box on the top right ‘1.5°C scenario‘ to see that a 66% chance of succeeding means that (as of 18 March 2022), we can emit no more that 309Gt. At the current rate of emissions, that’s July 2029.

Bankrupting the Carbon Budget:

What tipping points mean for the carbon budget

In Bankrupting the Carbon Budget: Part I, tipping points were explained in Videos 1 and 2.

Others tipping points include wildfires in the Arctic and Australia. Together these released around 1Gt of CO2 in 2020. The devastation was so great in places that the conditions that led to the evolution of these ancient ecosystems no longer exist. ‘Zombie’ wildfires in boreal forests in Siberia and Canada and Alaska continue to burn peat underground over winter, re-igniting record-breaking forest fires in the summer of 2021.

These forests, which make up large parts of the biosphere that once absorbed carbon and locked it away, are now releasing carbon to the atmosphere together with human-caused emissions. They have passed a tipping point; a point of no return. The countdown clock in Fig. 1 doesn’t include these emissions because the compound effects are so complex, they have yet to be included in Earth systems models used by the Intergovernmental Panel on Climate Change (IPCC).

But the atmosphere doesn’t care where these emissions originate. Nor how much nations—most notably New Zealand—or businesses cheat on their carbon accounting. The reality is that the carbon budget is a globally shared account. Governments think they know how much we have left to ‘spend’, but the burning forests and melting permafrost and methane clathrates are making CO2 withdrawals over which we have no control. All we know is that somewhere between warming of 1-2°C, some tipping points will be irreversible and warming will accelerate, causing even more tipping points to fall like dominoes.

A race against time

Currently, atmospheric CO2 is around 418ppm and climbing 2-3ppm every year. Global average temperatures are 1.2°C and rising. The last time CO2 in the atmosphere exceeded 400ppm was during the Pliocene Epoch (2.6-5.3 million years ago). Global average temperatures were 2-3°C warmer, Antarctica was 14°C warmer, and melting ice caps added 10-20 metres to sea levels.
 
So why aren’t we already that hot?


The relationship between the amount of CO2 in the atmosphere and warming is well-understood physics and chemistry. But there is a delay—a lag time of 10-20 years—between adding CO2 to the atmosphere and warming. So even if we switch off all emissions today, things will get hotter over the next two decades. It takes even longer for melting icecaps to raise sea levels, unless there’s an abrupt Meltwater Event (historically, these have raised sea levels as much as 4m/century).

The IPCC is banking our future existence on the lag time to literally buy us time to drawdown enough CO2 from the atmosphere and permanently store it back where it came from, with fingers crossed that will return the planet to a safe operating space of 350ppm. 

The Plan: built-in assumptions

The crucial thing about The Plan is that it depends entirely on assumptions. The most important assumption is that carbon capture technologies will draw down and safely store CO2 underground before warming triggers irreversible tipping points. This assumption (otherwise known as magical thinking) is because there isn’t enough land on Earth to plant enough trees to offset emissions while still being able to grow food to feed an exploding global population:

“If we absolutely maximised the amount of vegetation all land on Earth could hold, we’d sequester enough carbon to offset about ten years of greenhouse gas emissions at current rates. After that, there could be no further increase in carbon capture.
 
“Together, land plants and soils hold about 2,500Gt of carbon – about three times more than is held in the atmosphere.
 
“In recognition of these fundamental constraints, scientists estimate that the Earth’s land ecosystems can hold enough additional vegetation to absorb between 40 and 100Gt of carbon from the atmosphere. Once this additional growth is achieved (a process which will take a number of decades), there is no capacity for additional carbon storage on land.”

– Bonnie Waring, Senior Lecturer, Grantham Institute, Climate Change and Environment, Imperial College London

In spite of this limitation, deploying natural climate solutions (NCS) to draw down carbon into restored natural ecosystems would help restore critical, life-supporting ecosystem services.
 
Because we literally cannot live without these services, including their role in climate adaptation and mitigation, every government and council should be treating natural ecosytems as critical natural infrastructure. This is a higher-order priority than critical built infrastructure. Built infrastructure cannot exist without natural infrastructure, whereas natural infrastructure does not need built infrastructure.
 
So, what does The Plan look like?

The Plan by the numbers: 2019 – 2050

  • Atmospheric concentration at the start of 2019: 408ppm
  • Emit: no more than 400Gt of CO2 over the next 21 years; this would add around 23ppm to the atmosphere.
  • Offset emissions: as some emissions are unavoidable, they must be 100% offset by drawing down the same amount of CO2 as emitted and storing it permanently underground or in natural ecosystems. Plantation forestry is by definition not permanent, so it shouldn’t be regarded as a permanent offset because the carbon in it is recycled back into the atmosphere.
  • Draw down: an average 3.9Gt of CO2 every year (total 81.9Gt between 2019-2050) and store it underground and in natural ecosystems. In total, this would remove around 10.5ppm. Again, plantation forestry shouldn’t be regarded as a permanent drawdown.
  • Together, The Plan means that atmospheric concentration as of January 2050  will be: 408ppm + 23ppm – 10.5pm = 420.5ppm.
  • Limitations to offsetting and drawdown:
    • The world’s terrestrial ecosystems can only hold between 40 and 100Gt, so by 2050, CO2 will need to be permanently stored elsewhere.
    • Burning forests and melting permafrost and methane clathrates are emitting CO2 and methane. We don’t know how much, we have no control over it, but we do know this is eating into the existing carbon budget.

The Plan by the numbers: 2050 – 2100

  • The planned atmospheric concentration at the start of 2050: 420.5ppm
  • Emit: zero CO2
  • Offset: As some emissions are unavoidable, they must be 100% offset by drawing down the same amount of CO2 as emitted and storing it permanently underground. By now, terrestrial ecosystems will be unable to store any more carbon.
  • Draw down average 24Gt/year until 2100 (24Gt x 50 years = 1,250Gt or 72ppm) and store it…somewhere.
  • Planned atmospheric concentration at the start of 2100: 420.5ppm – 72ppm  = 348.5ppm.
  • Limitations to offsetting and draw down:

The Plan: how are we doing so far? 2019 – 2021

  • Atmospheric concentration at the start of 2019: 408ppm
  • Atmospheric concentration at start of 2022: 418ppm, ie, we’re going to hit  420.5pm before 2024, not 2050.
  • Emitted: 107Gt of CO2 (26.7% of the 21-year budget ‘spent’ in 3 years)
  • Offset: A handful of the world’s largest carbon polluters are buying up most of the land available for afforestation/reforestation to offset their emissions, leaving no available land for others to offset theirs. This includes land needed to feed people. Many are investing in low value or ‘ghost’ forests such as palm oil plantations, because plants that grow faster earn far more money from carbon credits. Many corporations have no plans to ever become carbon neutral because they will pass the cost of cheap and often useless offsets onto customers. The New Zealand Government, which is using taxpayer dollars to subside the eye-watering carbon cost of agriculture (giving them a 95% discount on emissions), and Fonterra, our largest carbon polluter, also plan to buy carbon credits offshore because they’re cheaper.
“New Zealand’s proposals to COP-26 were dismaying, seeking to shift the task of seriously tackling climate change to others. Spending five billion dollars on international credits to ‘restore’ forests overseas when our own forests are dying is like investing in someone else’s business when your own is going bankrupt. It’s irresponsible.”
 
– Dame Anne Salmond, Distinguished Professor in anthropology at the University of Auckland, and 2013 New Zealander of the Year.

  • Draw down: In spite of all the reforestation and rewilding projects around the globe, terrestrial ecosystem destruction (land use change) exceeded reforestation and offsetting by approximately 10Gt (Fig. 2). A large chunk of these losses are from the Amazon, parts of which have become so dry that they can no longer support re-forestation, so they’re turning in savannahs or being used to grow palm oil, soya, and methane-emitting cows.
  • Limitations to offsetting and drawdown:
    • Oddities with emissions trading schemes not accounting for the value of carbon locked in established forests and their soils, has created perverse incentives: old-growth and naturally regenerating forests are being cut down and/or burned so they can be replaced by fast growing monoculture crops like pine forests that earn more from carbon credits (if they survive wildfires and rapidly rising temperatures). And COP26 did nothing to prevent this from happening into the future (scroll down).
    • The only company extracting CO2 and permanently storing it underground (versus selling it as fuel) is in Iceland. In September 2021, Climeworks’ operations scaled up. It now draws down and stores 4,000 tonnes CO2/year. To scale up to 3.9Gt/year (‘The Plan’) would require building and deploying 9.5 million additional fully operating plants of the same size. To scale up to 24Gt/year from 2050 onward would require 58.5 million additional fully operational plants of the same size. And then there’s this:

“No artificial machines that are even in the design stage will also clean our air, clean our water, provide habitat for wildlife and all the other useful features of trees.” – Sophie Bertazzo, Senior editor, Conservation International

Fig. 2. Sources of carbon emissions 2021 (Image: www.co2.earth/global-co2-emissions)
Fig. 2. Sources of carbon emissions 2021 (Image: www.co2.earth/global-co2-emissions)

COP26: bankrupting the carbon budget

“We are on the verge of the abyss, and when you are on the verge of the abyss, you need to be very careful about what the next step is.  And the next step is COP26 in Glasgow.”

– Antonio Guterres Secretary General for the United Nations
 
Video 1: “I apologise for the way this process has unfolded. I am deeply sorry. I also understand the deep disappointment but I also think, as you have noted, that it is vital that we protect this package.”

– Alok Sharma, President COP26 following last minute changes from India and China.
 
Sharma apologised because India and China hijacked the meeting in the last minutes, demanding that the wording of the final agreement be that coal would be ‘phased down’ not ‘phased out’. China, the world’s largest emitter, won’t commit to net zero until 2060. India, whose emission are increasing fast every year, won’t commit to net zero until 2070. 
 
As Sharma pointed out, the final package, as weak as it was, brings agreement to the rules in Paris Agreement. And, while it’s taken 165 years, fossil fuels have now been formally recognised as the primary driver of climate change.
 
The ‘Reducing Deforestation’ COP26 Article
 
This looks like a win…except that the same declaration was also made 17 years ago, after which deforestation subsequently increased:
“The Glasgow declaration on forests and land use is a pledge to end or significantly reduce deforestation by 2030… In 2014 the New York declaration on forests promised to cut deforestation by 50% by 2020 and end it completely by 2030. Since then there’s been an increase in global deforestation contributing an estimated 23% to total global CO2 emissions.

“Under the UN rules, man-made plantations count as forests even though they contain none of the rich ecosystems and biodiversity of indigenous forests. Environmental groups worry that a big chunk of the $19.2 billion dollars allocated to the Glasgow declaration will be used to tear down existing forestry land to create more of these plantations for things like palm oil, paper and wood pellets, instead of preserving and protecting the trees and plants and wildlife that are now so critically endangered. 

“And how about this doozy: the declaration’s terminology of deforestation refers to ‘permanent loss of forests when land is fully converted to some other use like agriculture or development’. It’s almost completely silent on the role of traditional logging in driving forest degradation from within. Under this agreement loggers can still disappear deep inside a rainforest like the Amazon and destroy forest biodiversity and carbon stocks resulting in almost exactly the same devastating impacts as true deforestation.”

– David Borlace, Video 2 (below)
 
Between 2012 and 2018, New Zealand indigenous land cover area decreased by 12,869ha. In 2020 alone we lost 8,530ha of native forest. There is no reason to expect that trend or enforcement of current or future policies to reverse that trend.
 
So where does that leave us?
 
Carbon Brief has done a full analysis of the outcomes. If every country actually delivers on their promises and statements made at COP26, warming will be around 2.4°C. But that was before India and China insisted in last minute changes. China, India, Australia, and Russia announced plans to open more coal mines. And oil production from OPEC increased.
Climate Action Tracker breaks down the numbers (Fig. 3).
 
The most commonly repeated mantra that you’ll hear on the news, is that to stay within 1.5°C target, global emissions need to fall 45% by 2030. But that’s based on The Plan. The countdown clock at the top of the page, which reflects what’s actually happening in the atmosphere, is clear: to have a 66% chance of staying under 1.5°C emissions need to fall to zero by 2027. As we have no control over the growing emissions from wildfires, melting permafrost and methane clathrates, we had also better start drawing down and permanently storing CO2 as fast as possible.

Fig. 3. The most optimistic scenario of 1.8C (pale blue box) requires every single country to meet every single promise and every single target by 2030. This does not include tipping points (Image and linked PDF report: Climate Action Tracker. )
Fig. 3. The most optimistic scenario of 1.8C (pale blue box) requires every single country to meet every single promise and every single target by 2030. This does not include tipping points (Image and linked PDF report: Climate Action Tracker. )

COP26: The oceans

As Bonnie Waring said in the quote above:

“If we absolutely maximised the amount of vegetation all land on Earth could hold…”

The oddity in The Plan is that it largely ignores 70% of the surface of the planet that’s not land: the oceans, or more specifically the blue carbon in them. For the first time, the capability of the oceans to rapidly draw down and permanently store vast quantities of CO2 was finally addressed at COP26.

New Zealand has an exclusive oceanic economic zone 14 times larger than our land area. Why isn’t the government (and heavy carbon polluters) using that incredible capacity to invest far more in locally produced blue carbon? Fed by the sun, with no need for irrigation or agricultural chemicals, some species can grow up to 1m/day, drawing down as much as five times more carbon dioxide from the atmosphere than rainforests, and permanently sequestering if not harvested and instead, cut and dropped into deep ocean.

Watch this (deep blue) space.

Video 2 : Comprensive 18-minute analysis of COP26
 

More information

  • COP26: The final draft
  • Glasgow’s 2030 credibility gap: net zero’s lip service to climate action: Climate Action Tracker
  • Detailed analyses of each component of COP26: Carbon Brief (scroll down the page a bit to see the links to each section)
hottest days

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We need carbon. We need water, too. But like all good things, there can be too much. Too little water and we die of thirst. Too much, we drown. The same with carbon. Too little in the atmosphere in the form of carbon dioxide (CO2), we go into an Ice Age. Too much, the planet broils. We know this because of the geological evidence and from fundamental laws of physics and chemistry.

How much carbon is there?

There is about 1.85 billion, billion tonnes of carbon on Earth. More than 99% is beneath our feet in soil and rocks including fossil fuels and permafrost. Just 0.2% or 43,500Gt is above the surface. Through natural processes, carbon is constantly in flux. That is, it’s moving between the land, the oceans, and living things (see ‘carbon cycle’ this website). When it’s burned, melted, or respired, it becomes a gas, combining with oxygen to make CO2. Some ends up in the atmosphere*. The rest is absorbed by terrestrial and oceanic ecosystems: forests, grasslands, wetlands, and marine animals and plants that make more than half the oxygen we breathe, and also as carbonic acid (H2CO3) dissolved in ocean and lake waters.

*Calculations at the bottom of this page.


A shift in time

It doesn’t take much CO2 in the atmosphere to warm the planet. Some 18,000 years ago, the concentration of CO2 was 189 ppm (parts per million). Global temperatures were 7-9°C cooler than today, and ice sheets several kilometres thick covered most of Europe and North America.

Over the next 10,000 years, the concentration increased 72ppm, to reach 261ppm. That was enough to warm the planet 6-8°C (Fig 2.).

Fig. 2: The blue line shows globally averaged surface air temperature from 24,000 years ago to the present day, compiled from paleoclimate records with a computer model of the climate system. The horizontal scale has been stretched for the past 1,000 years to show recent changes. Warming begins at the end of the last Glacial around 18,000 years ago, then temperatures stabilize around 9,000 years ago until the last 170 years, when excessive greenhouse gasses triggered rapid warming. (Image: Osman et al /Nature).
Fig. 2: The blue line shows globally averaged surface air temperature from 24,000 years ago to the present day, compiled from paleoclimate records with a computer model of the climate system. The horizontal scale has been stretched for the past 1,000 years to show recent changes. Warming begins at the end of the last Glacial around 18,000 years ago, then temperatures stabilize around 9,000 years ago until the last 170 years, when excessive greenhouse gasses triggered rapid warming. (Image: Osman et al /Nature).
 
By then, some 8,000 year ago, the warming had created a comfortable, and crucially a stable and predictable enough climate to enable humans to plant crops, domesticate livestock, and build civilizations. This land-use change added about 400Gt of CO2 to reach a concentration of 284ppm by the year 1850.
 
Courtesy of our planet’s eccentric orbit around the sun, the Earth was also entering a gradual cooling cycle that would ultimately lead to another Glacial epoch. This orbital obliquity largely compensated for the gradual warming effect of the extra carbon in the atmosphere. Aside from a few small climatic blips caused by volcanoes and the sun’s activity, the global climate remained stable enough for human civilization to reach a technological watershed moment: the Industrial Revolution.
 
To power this revolution, we dug carbon out of the ground and burned it to fuel ever-larger machines, fishing fleets, and massive land use changes to feed ever more people, destroying vast natural ecosystems that once locked away millions of tonnes of carbon. Their burned remains entered the atmosphere as CO2. (Slaughtering countless whales may have added quite a bit, too). In the 100 years from 1850 to 1950 we added, either directly or indirectly, another 450Gt of CO2 to the atmosphere, and so concentrations reached 310ppm.
 
It was about to get worse. Between 1950 and 2000—just 50 years—we added around 1050Gt; more than twice as much as we’d added the previous 7,950 years. Atmospheric CO2 passed 370ppm. Shoveling so much carbon into the atmosphere had postponed the inception of the next Glacial epoch by 100,000 years.
 
The terrestrial and ocean ecosystems that once supported us continued to being burned and bulldozed. And the pace of destruction kept increasing. The ocean, which had been absorbing more than 90% of the extra heat and as much as half the excess CO2, was becoming dangerously acidic. 
 
Twenty-one years later, on 21 April 2021, atmospheric CO2 passed 420ppm* for the first time in several million years. Our planet is now heating up faster than at any time since the comet wiped out the dinosaurs 65 million years ago. And the oceans are now absorbing only about 25% of it.
 

*The average for 2021 will be about 417ppm because atmospheric concentrations change between summer (lower) and winter (higher); see the graph below for an explanation.

The carbon budget

When governments signed the 2015 Paris Agreement they did so promising to keep global warming under 1.5°C by staying within a carbon budget. Each nation could choose how they would achieve this by reducing emissions—carbon ‘spending’—and increasing carbon ‘savings’ by planting carbon-absorbing trees. Obviously, to stay within the global budget, every nation had to play its part.

They didn’t. Emissions increased (Fig. 3)

Fig. 3: Emissions 2015-2021 * (projected (Image: co2.earth).
Fig. 3: Emissions 2015-2021 * (projected (Image: co2.earth).
In 2021, the IPCC presented a stark warning. Since the beginning of the Industrial Revolution, we’ve added about 2,400Gt of CO2 the atmosphere, around a third of which we added in just the past 20 years. To have a 66% of staying within 1.5°C, starting from January 2020, the world could emit no more than 400Gt of CO2. 
 
Emissions in 2020 were 38Gt. Emissions in 2021 are projected to be around 39Gt (Fig. 3). That leaves around 323Gt in the budget if we’re prepared to live with a 66% chance of keeping temperatures under 1.5°C. Or we can spend another 421Gt to have a 50% chance.
 

And only if one-way climate tipping points, don’t tip.

 

Tipping points are tipping

Scientists had been saying for decades that warming between 1 to 2°C would trigger catastrophic tipping points. At 1.2°C our climate is now already too hot to refreeze the 10,000 cubic metres of ice melting every second from Greenland’s ice sheet. So much freshwater entering the North Atlantic is already changing oceanic currents. This is triggering more tipping points in a cascade effect that will lead to irreversible chain reactions and rapid warming well beyond 3°C. Unless COP26 brings radical and immediate changes, the planet is destined to enter an entirely new ‘hothouse’ state, one we cannot control or reverse. And one hostile to our existence.
 

“The drama here is that one characteristic of tipping points is that once you press the ‘on’ button you cannot stop it; it takes over. It’s too late. It’s not like you could say, ‘Oops, now I realize I didn’t want to melt the Greenland ice cap. Let’s back off.’ Then it’s too late.” – Johan Rockström, Breaking Boundaries: The Science of Our Planet (Video 1)

Other tipping points are also pushing the carbon budget to the edge of a potential freefall. This includes vast areas of permafrost—frozen soil that contains an estimated 1,600Gt of carbon, almost twice the amount in the atmosphere today—is melting, disgorging CO2 and the far more potent greenhouse gas, methane into the atmosphere. And the Amazon rainforest, which could potentially releasing 200Gt of carbon into the atmosphere over the next 30 years. That is, by 2050. This process has already begun in south-east Amazonia (Video 2).
 
Earlier this year, the World Meteorological Organization stated that at least one of the next 5 years will be 1.5°C* warmer than pre-Industrial levels. And the chance of this happening is increasing with time.
 
Would you send your kids to school knowing they had just a 66% chance of coming home alive? Or 50% if we emit an extra 21Gt over the budget? And every day, the odds of their survival are getting increasingly worse because emissions are increasing. That’s what the carbon budget means for their futures.
 
Kids have done those simple calculations. And that’s why they’re so angry.
 
*The internal variability in any single year is estimated to be ± 0.25°C, so a single year at 1.5°C could be compensated if the following years are much cooler.
 
Video 1: in ‘Breaking Boundaries: The Science of Our Planet’, Sir David Attenborough succinctly explains tipping points. This is a short version of the full documentary of the same name, available on Netflix. 
Video 2: Amazon carbon tipping point

More information