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Extreme CO2 Levels Could Trigger Clouds 'Tipping Point' and 8C of Global Warming (carbonbrief.org)
If atmospheric CO2 levels exceed 1,200 parts per million (ppm), it could push the Earth's climate over a "tipping point", finds a new study. This would see clouds that shade large part of the oceans start to break up. From a report: According to the new paper published in the journal Nature Geoscience, this could trigger a massive 8C rise in global average temperatures -- in addition to the warming from increased CO2. The only similar example of rapid warming at this magnitude in the Earth's recent history is the Paleo-Eocene Thermal Maximum 55m years ago, when global temperatures increased by 5-8C and drove widespread extinction of species on both the oceans and land.
However, scientists not involved in the research caution that the results are still speculative and that other complicating factors could influence if or when a tipping point is reached. The threshold identified by the researchers -- a 1,200ppm concentration of atmospheric CO2 -- is three times current CO2 concentrations. If fossil fuel use continues to rapidly expand over the remainder of the century, it is possible levels could get that high. The Representative Concentration Pathways 8.5 scenario (RCP8.5), a very high emissions scenario examined by climate scientists, has the Earth's atmosphere reaching around 1,100ppm by the year 2100. But this would require the world to massively expand coal use and eschew any climate mitigation over the rest of this century. Further reading: A state-of-the-art supercomputer simulation indicates that a feedback loop between global warming and cloud loss can push Earth's climate past a disastrous tipping point in as little as a century.
However, scientists not involved in the research caution that the results are still speculative and that other complicating factors could influence if or when a tipping point is reached. The threshold identified by the researchers -- a 1,200ppm concentration of atmospheric CO2 -- is three times current CO2 concentrations. If fossil fuel use continues to rapidly expand over the remainder of the century, it is possible levels could get that high. The Representative Concentration Pathways 8.5 scenario (RCP8.5), a very high emissions scenario examined by climate scientists, has the Earth's atmosphere reaching around 1,100ppm by the year 2100. But this would require the world to massively expand coal use and eschew any climate mitigation over the rest of this century. Further reading: A state-of-the-art supercomputer simulation indicates that a feedback loop between global warming and cloud loss can push Earth's climate past a disastrous tipping point in as little as a century.
The problem here is that studies like this are based on *simulations* not observations of repeatable experiments. What we have here is a set of theories, which really cannot be proven beyond doubt.
If we are being honest here, climate change science is, at best, an educated guessing game, not a proven beyond a doubt set of scientific laws, and specifically I mean "man made climate change." The critics of this science have some valid points. Past high profile predictions of our demise from climate change have been wildly over blown, there seems to be a bias towards "making news" in order to get research grants, and little attention is paid to the views of those who disagree with the consensus.
You may not agree with them, but there are some valid objections being raised, objections that simply cannot be dismissed with a wave of the hand or by calling folks stupid.
Simulations have serious limits. It's nearly impossible to prove your models are good enough and your initial starting data resolution is accurate enough to give you reasonably good approximations of the future, even more so as your time frames move further and further out. To put it bluntly, climate simulations are less and less useful the longer you run the simulation into the future. Any fanciful claims made about the far reaches of a simulation, where the precision of the simulated results starts to get very poor, should be generally ignored. But we are slumming for funding here, so they fire off the press release...
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
Climate change is real
So is continental drift. Earthquakes kill thousands of people every decade. I propose a new tax to prevent continental drift and deal with all these earthquakes.
Seven puppies were harmed during the making of this post.