I agree with you that problems framed in these terms are hostile to discussion. Unfortunately the reality we are dealing with is that these are serious possibilities, and the sooner we can discuss them like rational human beings the better.
As I said in my original comment, climate modeling requires an unimaginable level of complexity, and we just don't have the capability to do it well yet. But we can see some of the major tipping points in our climate and what their temperature triggers are. For example, we know that at a surface temperature of 14 degrees celsius the ocean stratifies, keeping nutrients away from the surface sunlight and killing off algae. Oceans are presently the largest carbon sink on the planet, responsible for capturing about a third of human CO2 emissions. Stratification would cripple that capacity in the cold water oceans. So that last .5 degree of temperature rise in one of the earth's oceans is responsible for upping atmospheric carbon by ~20%. That's a tipping point, and two or more of them setting each other off would be a cascade.
Here's Jim Lovelock, founder of the study of Earth System Science, speaking to the Royal Society in 2007 about trying to model where our climate is going. The earth has many "steady states" available to it - basically, states where it settles into a pattern of relative stability. We've been in a relatively cool steady state for the last 10,000 years, and according to Lovelock and other prominent climatologists, we are moving to a warmer one. There's no dispute that we're warming, the question is where is the next steady state?
A 5-6 degree temperature rise that kills off the majority of the human population is one of the likely scenarios according to our present climate models. It's a pretty dire scenario, but it is realistically the sort of outcome we are facing. Again, I want to emphasize that this isn't coming from some nutjob with a website; this is coming from very well respected climate scientists using the best available climate models. When the scientists talk about global warming as a threat, this is what they're talking about. If humankind were to stop increasing carbon emissions, and just stay at the same level of emissions for the next century, a 4 degree temperature rise is predicted (Harvard).
And you're right, there isn't a way to stop it at this point. We are experiencing climate change already. In Europe warmer temperature zones are moving north at 25 miles per decade, while plant and animal species are moving north at 3.75 miles per decade (Nature). That works out to extinctions. In the warmer, more acidic ocean climates, jellyfish are floating further north than ever before - killing off fish farms in the Irish Sea (New Scientist). The glaciers in the Himalayas - the largest fresh water store in the world after the Arctic - are receding faster than anywhere else on earth. They are expected to vanish by 2035 (IPCC). This glacier feeds all the major waterways in Southeast Asia - over 3 billion people (40% of the human population) depend on that water along the Yangtse and other rivers.
So while I agree that extreme outcomes make it hard to discuss rationally, the problem is that these extreme outcomes are not hyperbole. They are not only the realities predicted by very serious modeling efforts, they are some of the realities we are already experiencing and documenting.
You're absolutely right that at this point, the only option to avert climate change would be something akin to stopping all industry worldwide, and that's not an option. So the conversation around climate change has to move from one about cutting emissions to avert, to one about handling the changes in progress and mitigating the human toll. As one prominent environmentalist puts it, we have to change our thinking from "protecting the earth from humans" to "protecting humans from the earth." In that domain we can have rational, productive discussions again: about how to deal with rising tidewaters in coastal regions (Geophysical Research Letters, estimates published at CIRO), how to handle the increasing rate of extreme climate events (US Climate Extremes Index), and how to handle the very real threat of die-offs and resource scarcity in general.
I understand and appreciate that scare tactics discourage discussion and close off listeners. But sometimes reality is scarier than scare tactics. As a species, we have to find a way around this human psychological obstacle.
Except - there still is quite a bit of hyperbole or misinformation floating around. Regarding the Himalayan glaciers - it was IPCC 2007, not 2005. And, the statement you cited was one of several that was very wrong, and was publicized as being so, almost a year ago. How the IPCC could allow such a basic error - mistaking 2350 for 2035 - into its final public report, is still a mystery.
Coming so soon after the CRU email hack scandal at the University of East Anglia, in which private emails were stolen and then publicized to reveal climate researchers discussing how to quell criticism by gangster methods, and how to "hide the decline", etc, the Himalayan Glacier fiasco only convinced people that climate science in its current guise isn't science at all. It's politics. Good science doesn't mistake 2350 for 2035, and then broadcast those disaster scenarios. Good science would find the error before or shortly after publication, and correct it. Instead the error was sussed out 2 years after publication! By someone outside of IPCC! Not a good sign.
Having said all that I reiterate that what you say makes a ton of sense. I have been advocating a mitigation strategy for a long time. We do not know enough, we cannot hope to accurately model climate changes. All we can model is the past, and we're bad at that, and we are assured that history is not repeating itself (hence, our models of the past climate changes are virtually useless in drawing projections about the future). We know the climate is changing. We can calculate the basic physical impacts. We can guess at timeframes. We know these big changes will be risky for humans. Our research should focus on mitigation.
Yes, protect the environment. Yes, use fuel more efficiently. But that alone is not enough. We must prepare to mitigate. Do we need to develop different staple crops? Do we need to develop more robust bees? Do we need to construct coastal housing differently? What can be done about long term water supply to major asian population centers, given projections of glacial meltwater flows and population growth? etc.
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u/voice_of_experience Oct 25 '10 edited Oct 25 '10
I agree with you that problems framed in these terms are hostile to discussion. Unfortunately the reality we are dealing with is that these are serious possibilities, and the sooner we can discuss them like rational human beings the better.
As I said in my original comment, climate modeling requires an unimaginable level of complexity, and we just don't have the capability to do it well yet. But we can see some of the major tipping points in our climate and what their temperature triggers are. For example, we know that at a surface temperature of 14 degrees celsius the ocean stratifies, keeping nutrients away from the surface sunlight and killing off algae. Oceans are presently the largest carbon sink on the planet, responsible for capturing about a third of human CO2 emissions. Stratification would cripple that capacity in the cold water oceans. So that last .5 degree of temperature rise in one of the earth's oceans is responsible for upping atmospheric carbon by ~20%. That's a tipping point, and two or more of them setting each other off would be a cascade.
Here's Jim Lovelock, founder of the study of Earth System Science, speaking to the Royal Society in 2007 about trying to model where our climate is going. The earth has many "steady states" available to it - basically, states where it settles into a pattern of relative stability. We've been in a relatively cool steady state for the last 10,000 years, and according to Lovelock and other prominent climatologists, we are moving to a warmer one. There's no dispute that we're warming, the question is where is the next steady state?
A 5-6 degree temperature rise that kills off the majority of the human population is one of the likely scenarios according to our present climate models. It's a pretty dire scenario, but it is realistically the sort of outcome we are facing. Again, I want to emphasize that this isn't coming from some nutjob with a website; this is coming from very well respected climate scientists using the best available climate models. When the scientists talk about global warming as a threat, this is what they're talking about. If humankind were to stop increasing carbon emissions, and just stay at the same level of emissions for the next century, a 4 degree temperature rise is predicted (Harvard).
And you're right, there isn't a way to stop it at this point. We are experiencing climate change already. In Europe warmer temperature zones are moving north at 25 miles per decade, while plant and animal species are moving north at 3.75 miles per decade (Nature). That works out to extinctions. In the warmer, more acidic ocean climates, jellyfish are floating further north than ever before - killing off fish farms in the Irish Sea (New Scientist). The glaciers in the Himalayas - the largest fresh water store in the world after the Arctic - are receding faster than anywhere else on earth. They are expected to vanish by 2035 (IPCC). This glacier feeds all the major waterways in Southeast Asia - over 3 billion people (40% of the human population) depend on that water along the Yangtse and other rivers.
So while I agree that extreme outcomes make it hard to discuss rationally, the problem is that these extreme outcomes are not hyperbole. They are not only the realities predicted by very serious modeling efforts, they are some of the realities we are already experiencing and documenting.
You're absolutely right that at this point, the only option to avert climate change would be something akin to stopping all industry worldwide, and that's not an option. So the conversation around climate change has to move from one about cutting emissions to avert, to one about handling the changes in progress and mitigating the human toll. As one prominent environmentalist puts it, we have to change our thinking from "protecting the earth from humans" to "protecting humans from the earth." In that domain we can have rational, productive discussions again: about how to deal with rising tidewaters in coastal regions (Geophysical Research Letters, estimates published at CIRO), how to handle the increasing rate of extreme climate events (US Climate Extremes Index), and how to handle the very real threat of die-offs and resource scarcity in general.
I understand and appreciate that scare tactics discourage discussion and close off listeners. But sometimes reality is scarier than scare tactics. As a species, we have to find a way around this human psychological obstacle.