"Terrorists kill people. Weapons of mass destruction have the potential to kill an enormous amount of people," Mr. Bloomberg told reporters after addressing the U.N. General Assembly, but "global warming in the long term has the potential to kill everybody."
http://www.nysun.com/article/71103

Terrorist has and is killing large amounts of people. Terrorism is killing the old, the young and those in the middle. This terrorism has mostly killed Muslims.
Of the soldier combating it, many are dying, and again mostly Muslim soldiers. But worst thing that terrorists kill is hope- and this exactly one of the things they "hope" to achieve and is about only objective they have been somewhat successful at achieving.

Global warming hasn't killed anyone. Increased CO2 levels haven't killed anyone, rather about the only thing really significant that can be said about increased global CO2 levels is it has increased crop productivity- thereby reduce the land area needed for farmland and of course made it more profitable for farming. And in the US, I would guess [SWAG] that the increase in crop productivity due to increasing levels of CO2 has more than offset the farmland wasted to generate Ethanol for govt subsidies, but globally there is little doubt that the increase in CO2 has significantly increase crop yields, and thereby in countries such as India and China have prevented millions from starving to death.

The use of fossil fuel has been largely responsible element in increasing global wealth. It has been and still is a means of getting cheap horsepower. And thereby has replaced animal and human physical labor with machines providing the power. Centuries ago this would have been considered an impossible dream, but today instead seeing this, some people instead pine for the days of harsh labor which has low productivity and lots of grinding misery. They few people who wish to return to earlier ways without using fossil fuel, are generally people who have never done a hard day's labor and live lifestyles that noblemen and kings of the past would deeply envied. And live average lifespan that easily exceeded all but a fortunate few.