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Planet At Risk of Heading Towards Irreversible 'Hothouse Earth' State (vice.com)
An anonymous reader quotes a report from Motherboard: What we do in the next 10-20 years will determine whether our planet remains hospitable to human life or slides down an irreversible path to what scientists in a major new study call "Hothouse Earth" conditions. Hothouse Earth is an apocalyptic nightmare where the global average temperatures is 4 to 5 degrees Celsius higher (with regions like the Arctic averaging 10 degrees C higher) than today, according to the study, "Trajectories of the Earth System in the Anthropocene," published Monday in the Proceedings of the National Academy of Sciences. Sea levels would eventually be 10-60 meters higher as much of the world's ice melts. In these conditions, large parts of the Earth would be uninhabitable. Cutting carbon emissions to limit climate change to 2 degrees C, as proposed in the Paris climate agreement, won't be enough to avoid a "Hothouse Earth," said co-author Johan Rockstrom, executive director of Stockholm Resilience Centre. The reality is that global temperatures aren't driven by human emissions of carbon alone, says Rockstrom -- natural systems such as forests and oceans also play a major role. If global warming reaches 2 degrees C it could trigger a feedback, or "tipping element," in one or more of our natural systems and drive further warming, Rockstrom told Motherboard. To put that into perspective, the recent heat waves and wildfires are being linked to climate change that has raised the global average temperature 1 degree C. The researchers conclude the study on a more uplifting note, saying: "We have the knowledge and ability to act. This is within our control." There are three main areas of action that need to be taken within the next two decades. "The top priority in the coming decade is to aggressively cut carbon emissions and decarbonize our energy systems as quickly as possible," reports Motherboard. "The second priority is to halt deforestation and conversion of nature areas into agricultural production. Forests and other natural areas currently absorb 25 percent of our carbon emissions and this needs to grow." The third action is "to continue to develop technologies to pull carbon from the atmosphere and safely store it for thousands of years." While this last action can be costly, we're starting to see some companies give it a try. A startup called Climeworks recently inaugurated the first system that captures CO2 from the air and converts the emissions into stone, thus ensuring they don't escape back into the atmosphere for the next millions of years.
US emissions are down whilst EU - and China, and India - emissions are up. I'm sure this will get down-modded since it doesn't pay homage to the proper models, but facts are facts: and when facts and beliefs/models collide - facts win.
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
https://xkcd.com/1732/
Yeah, I know it's a cartoon and not precise scale but it's pretty blatant at the end of it, bad things are coming.
Combine this, with the recent discussion of methane finally escaping in siberia.
https://www.google.com.au/sear...
It's only a matter of time, we're well past the point of no return. I can't really fathom a good analogy, perhaps the titanic? Except 10,000 times larger and moving much, much slower but we're only 6 feet from the ice burg. We're gonna take a little bit to hit it, but rest assured we absoloutely will be hitting that ice burg.
Don't breed, having kids in the future that's coming is only more depressing.
US outsources not only production but also polution.
I'm a meteorologist but I've listened to enough geology and paleontology seminars to have a basic understanding of the climatic conditions many millions of years ago. You're correct that carbon dioxide levels have been substantially higher than in the present day and that life flourished under such conditions. The Earth has transitioned between two primary states, an icehouse state and a hothouse state. You can think of these as two equilibrium points in Earth's climate about which there are small oscillations. Displace the climate a bit from one of those equilibrium points and it tends to return back. It's much harder to push the climate to the other equilibrium point because a much larger displacement from the current equilibrium is required.
We're currently in an icehouse Earth, with long periods of glaciation and some brief interglacial periods. We're in one of those interglacial periods right now. Releasing enough greenhouse gases into the atmosphere and triggering other feedbacks in the climate system might push the Earth to the other equilibrium point. Such a transition might, indeed, be permanent due to the shifting habitable zone on geologic time scales.
I see two potential problems with this. One is that while the hothouse Earth might be conducive to supporting human civilization as it presently exists. The second is that such an abrupt transition period would be incredibly stressful for life in general. We're not currently seeing mass extinctions, but such a severe transition in climate could certainly trigger such an extinction. It seems likely that Earth would recover and life would thrive again in a hothouse Earth. However, in the previous mass extinctions, the recovery has been somewhere in the range of 2-10 million years depending on the severity of the event. The Permian-Triassic extinction came close to wiping out life on Earth and it's not entirely clear what caused this mass extinction.
We humans depend on the ecosystem beneath us to support human life. I don't believe anyone really knows where tipping points are. There's limited geologic evidence of many past transitions and mass extinctions like the aforementioned Permian-Triassic extinction. Even a less severe extinction event would have massive consequences for humanity. We don't really know what it takes to trigger a mass extinction event, but the geologic evidence we do have says it's something we dare not mess with. While I said it's likely life would recover, there's no guarantee it would include us.
We're not seeing mass extinctions and we don't really know what it would take to trigger such an event. Life can certainly thrive on a hothouse Earth, but that's little consolation if humans don't survive the transition. And mass extinctions aren't very kind to apex predators like what humans are.
Yeah thats kind of what frusturates me about the "Its been super hot before and things lived!" talking point. Sure it has, but unless your a serious misanthrope that doesn't want people to exist, it really does well to remember that life also exists around sulphur plumes at the bottom of the ocean, but not people! Hell, theres a good chance we could bio-engineer primitive life that'd cope on venus, maybe even mop up some of the atmosphere a bit so in a few thousand years we could live there. But for the time being, bad for humans.
Excuse the Unicode crap in my posts. That's an apostrophe, and slashdot is busted.
China has a very low birthrate - well under replacement. India, in the last couple years, has become sub-replacement. Mexico is essentially at replacement. So I don't know which "high birthrate" countries you're talking about. Essentially the only countries with high growth populations are in sub-Saharan Africa plus a handful of poor oddballs around the world (Pakistan being the largest of these).
source - note that world average replacement fertility is 2.3, lower in rich countries, higher in poor ones.
Please stop this childish bickering about who is the real boogeyman. Truth is, this is a global problem and it needs a global solution. Everybody has to start working together to fix civilization, or the planet will break us.
Yes, it's not about saving the planet, it's about saving human civilization. The planet doesn't care and will recover. Hundreds of thousands or millions of years aren't much in astronomical scales. Evolution will do it's thing, life will go on, but it will happen without us because we are not destroying the planet - we are destroying the environment that made it possible for humans to thrive.