U.S. opponents of the Kyoto protocol invariably speak of the economic costs of implementing measures to decrease greenhouse gas emissions, but they're not so vocal about the bottom line costs of extreme weather. As this BBC article points out, the insurance industry is reeling from the effects of the fourth warmest year since tracking began (according to the World Meteorological Organisation). The year 2004 was the most expensive ever for the insurance industry with record payouts for damages incurred from hurricanes, typhoons, and other natural disasters.
Factor in the expense of agricultural losses, health costs, destruction of wildlife, and similar costs and it is clear that the cost of not responding to global warming is the much greater expense.