MIT study says Arctic ice thinning 4x faster than predicted

But while I'm at it, how do you know we will suffer a great deal?

I am sure the climate is changing, I can read a graph of temperatures as well as the next guy. I am sure that humans are causing it, how could we not be considering our emissions? But how are we so damn sure that this is going to be a massive catastrophy?

There are predictions of doom and gloom in agriculture - but compare agriculture in 1750 to 1850 to 1950 to today. Would the farmers of 1750 even recognize the farms we have today? Technology is an amazing thing. We're not talking about making Earth 150 degrees, we're taking a 1-10 degree increase in average temperatures. That will definitely change our weather patterns, but how do we know we will starve to death? So what if the rain patterns change, you can't imagine some solar powered desalination plants and irrigation systems that rival how we move oil in pipelines today? You can't imagine genetically engineering crops to withstand slightly higher temperature changes or wet weather?

As for rising sea levels, so some property will be destroyed. It won't come as a breached levee or a tsunami, it will be gradual over years. Some people will have to move. At the end of the day, the populated areas will get levees.

It seems to me that we already have plenty of people suffering now due to natural disasters from earthquakes to hurricanes to tornados. If we are so willing to spend billions or trillions of dollars on preventing people from being hurt by the climate, why don't we fix some of the more pressing issues. Let's build homes in Haiti, China and Iran to Japan level earthquake standards. Why don't we move everyone out of trailer homes in tornado alley? Why don't we build massive tsunami walls in the Pacific? Those natural disasters kill hundreds of thousands of people. I don't see anyone saying climate change will kill hundreds of thousands of people, but we are far more willing to put into effect a tax on our economy to prevent that but not a tax on our economy to build new homes in other countries, or even to move people in our own out of unsafe homes. Why do we care that humans caused climate change and not mother nature?

If, however, we act to bring the climate out of the regime for which we have this evidence (for example, by raising the CO2 level to its highest value for 800,000 years), then with our present rudimentary understanding of the climate, we cannot predict what will happen with any great confidence. And, there is evidence that climatic changes can cause tremendous damage. So, the burden of proof should be on those who say that these changes are safe.

PS: Toss in even stronger and more frequent extreme weather and dumping CO2 is unlikely to end up as a good thing. At some point in the near future we are simply going to run out of oil so doing nothing does not mean we get to keep up our current approaches for all that long anyway.

'Just because it is unnatural and you are philosophically opposed to it?' is very much a projection of what you think the grandparent's underlying message is.

But while I'm at it, how do you know we will suffer a great deal?

I don't know, I speculate that there is a high probability of such because accelerated climate change seems to increase the probability of extreme weather events, both sudden and seasonal. Tornadoes and hurricanes fall into the former category, things like droughts or extended rainy seasons fall into the latter. While I don't think current weather events should be held up as evidence of climate change, we can look at current weather events to gain an idea of the potential costs and difficulties if the probability forecasts are accurate.

I don't see anyone saying climate change will kill hundreds of thousands of people, but we are far more willing to put into effect a tax on our economy to prevent that but not a tax on our economy to build [...]

You can't be paying much attention if you don't see warnings about increased loss of life. This is a major risk over the long term, from extreme weather as described above to damaged agricultural prospects, to intensified competition for access to shrinking resources such as land or clean water. We do not know the exact outcome or the costs, but we can form reasonable estimates and weight them in accordance with the known predictive ability of our models to do a cost-benefit analysis.

It strikes me as odd that those who are most skeptical of predictions about climate change are also the most sure of themselves when making statements about the economic impact, insisting that all 'green' expenditure constitutes a tax as if there were no positive externalities to be had from energy efficiency or less polluting forms of power generation.

As far as incalculable trillions: really? For one, monetary figures don't really cover it. A Bengali life is economically worth a couple tens of thousands at most, while an American one is worth millions. Their well being isn't captured by purely economic measures. That doesn't mean we should trade hundreds of Bengalis to save one American. There's also the libertarian point of view that, no matter how many SUVs an American might want, that doesn't give him a right to destroy a Bengali's home without his or her consent.

It's easy to hypothesize maybe some alternative policy response that involves a massive Marshall plan to... well, all the world. Do you think that's even vaguely plausible, though? I can't speak to European politics, but within America the chance of that ever happening is zero. Nada. Nil. No one wants to pay taxes even for their own schools and roads, let alone handouts, let alone foreign aid.

Why is it that most people who are concerned about the effects of climate change and invested in dealing with it think that pushing for more prevention is the best use of their efforts, not mitigation? I assume you wouldn't say they're all stupid.

Lastly, it's extremely controversial to suggest that the costs of prevention outweigh either (a) the costs of climate change itself or (b) the costs of mitigation. Unlikely, even--many places that use far less energy per capita than we do are hardly anti-technological dystopias.