My comment: Keep in mind, this five-to-twenty percent less economic activity figure is if we do nothing. If we invest and solve the problem, it’s the key to making the massive gains of the industrial era looking like child’s play. Why would we not invest to end global warming? It means clean power, perhaps unlimited power to drive generations of progress, not just lower sea levels.
SIR NICHOLAS STERN, the head of the British Government Economic Service, has produced the world’s first big report on the economics of climate change. … Sir Nicholas’s argument is that, far from undermining the American way of life, attempts to mitigate climate change may help preserve it. He argues this by setting the costs of allowing climate change to happen against the costs of mitigating climate change.
Previous estimates of the costs of climate change—as a result of more hurricanes, more floods and rising sea levels, for instance—have been somewhere between nothing and 2% of global GDP. But Sir Nicholas says those figures were wrong, for two reasons. First, the science has changed, and global warming seems to be happening faster than was previously believed. Second, those estimates have looked only at the likeliest outcomes from climate change, not at the outlying catastrophic possibilities. As a result, Sir Nicholas maintains that if greenhouse gas emissions go on increasing at their present rate, global output is likely to be between 5% and 20% lower over the next two centuries than it otherwise would have been.