A Swiss-American team of scientists has looked far into the future and calculated that the present lukewarm plans to limit climate change may involve too little action, applied too late.
Thomas Frölicher of ETH-Zurich and colleagues from Princeton report in Nature Climate Change that they tried to model the long-term planetary adjustment after carbon dioxide emissions from fossil fuel burning stopped altogether.
They simulated a planet in which greenhouse gas emissions continued to rise, until concentrations in the atmosphere had reached four times the pre-Industrial levels, and a total of 1,800 billion tons had been released into the atmosphere. And then the emissions stopped.
The consequences were unexpected. The carbon dioxide in the atmosphere would indeed gradually be absorbed by forests, crops, algae and other natural CO2 devourers; it would be incorporated into the calcium shells and corals and skeletons in the ocean and then slowly be tucked away as rock.
But after an initial period in which temperatures started to drop, something else happened. The simulated planet started to warm again, and go on warming for another 400 years or more.
Oceans’ influence dims
That is because although what scientists call “radiative forcing” – CO2 traps infra-red radiation and keeps the Earth’s temperature up – would begin to ease, the polar oceans that play such a powerful role in the climate machine would become less efficient at removing the surplus heat.
The logic of all this rests on the reasoning that life on Earth for the last 10,000 years has continued comfortably with a particular ratio of CO2 to other gases in the atmosphere. To increase carbon levels significantly – and this has already begun to happen – would therefore disturb this comfortable equilibrium, and then trigger a very long period of uncertainty.
Frölicher and colleagues found that 40 percent of the extra carbon in the atmosphere would have been soaked up within 20 years, and 80 percent within 1,000 years. This would of course affect temperatures.
First, as the carbon dioxide levels reached a maximum, the world would warm sharply and then, after 15 or 20 years, start to cool. The cooling could continue for a century.
Little time
But in the simulation, after the initial 100-year cooling-off period the Earth started to warm again. It went on warming for 400 years, by 0.37°C. This doesn’t sound much – but the Earth has already warmed by 0.85°C over pre-Industrial averages.
The world’s governments have collectively agreed that it would be good if the rise in average global temperatures could be halted at 2°C, and they have accepted in principle – serious concerted action has yet to be agreed – that with 500 billion tons of CO2 already released into the atmosphere, the safe limit should be 1,000 billion. But this now looks less plausible.
The Latest on: Global warming
- Climate Leaders Debate Goal for Controlling Global Warmingon April 27, 2024 at 3:45 am
A new U.N. program highlights the disconnect between climate messaging and the growing possibility of overshooting a key global warming threshold ...
- Global warming threatens Antarctica’s meteoriteson April 27, 2024 at 3:30 am
Antarctica is home to Earth’s largest concentration of meteorites — so many that over 60 percent of meteorite finds originate there. But global warming is endangering Antarctica’s meteorites, and a ...
- ‘Dismissing global warming? That was a joke’: Jeremy Clarkson on fury, farming and why he’s a changed manon April 26, 2024 at 10:00 pm
The former Top Gear presenter claims his controversialist persona was just a caricature, and he’s really a reformed character living the good life. But do old habits die hard?
- Octopuses could go blind due to global warmingon April 26, 2024 at 7:02 am
A recent study suggests that octopuses could face vision loss and survival challenges due to rising ocean temperatures.
- Global warming could make tides higher as well as raising sea levelson April 26, 2024 at 3:00 am
In addition to the overall rise in sea level, the heights of tides are also changing as the oceans warm and separate into more distinct layers ...
- Team develops new testing system for carbon capture in fight against global warmingon April 25, 2024 at 11:32 pm
More than 100 facilities designed to remove carbon dioxide (CO2) from the atmosphere are in various stages of development around the world. In the United States, the first direct air capture (DAC) ...
- Global warming intensifies stroke risk: Study links temperature swings to rising stroke burden worldwideon April 23, 2024 at 11:35 pm
Study found that non-optimal temperatures are responsible for over half a million stroke deaths globally in 2019, revealing significant variations in stroke burden due to temperature across different ...
- Breeding cows that fart less could help curb global warming: new studyon April 23, 2024 at 2:01 pm
The latest study, the first of its kind and published in the journal Climate this month, suggests that transforming farmland into forest or wetland would be most effective at reducing methane, but ...
- Europe is the fastest-warming continent, at nearly twice the average global rate, report sayson April 22, 2024 at 2:32 am
Two top climate monitoring organizations are reporting that Europe is the fastest-warming continent and its temperatures are rising at roughly twice the global average.
- How extreme cold events fit into the global warming modelon April 19, 2024 at 7:52 pm
Global warming is undeniable, yet recent winters have witnessed record-breaking, extreme cold temperatures in unexpected areas.
via Bing News
The Latest on: Climate Change
- The Power of Us: Climate change has disproportionately impacted these vulnerable US communities, experts sayon April 27, 2024 at 6:09 am
The disproportionate impacts of climate change on the poorest communities are already affecting pockets of the U.S.
- Is Russia ready for climate change? Mass floods expose lack of adaptation, campaigners sayon April 26, 2024 at 11:00 pm
Mass floods in Russia have thrown a spotlight on the country’s approach to managing the increasing risks it faces from climate change.
via Bing News