Climate change has direct and indirect consequences for human health. Heat waves affect health directly and are projected to take an increasing toll in developed and underdeveloped nations. Climate restricts the range of infectious diseases, while weather affects the timing and intensity of outbreaks.

Underlying many of these changes is the finding that, in the last half century, the world ocean has accumulated twenty-two times the amount of heat than has the atmosphere. Ocean warming is accelerating the global hydrological cycle, melting ice and leading to greater evaporation over some land areas, intensifying droughts, and heavier downpours elsewhere. Extreme weather events can create conditions conducive to “clusters” of infectious diseases.

Excess carbon dioxide itself carries health consequences. Ragweed grown in elevated carbon dioxide levels produces pollen disproportionate to its stem growth. Climate change is also affecting human health indirectly, by encouraging the spread of pests and diseases among livestock, wildlife, agricultural systems, forests and coastal marine life. Moreover, the exploration, extraction, mining, refining, transport and combustion of fossil fuels harm health and the environment, especially in developing nations.

On the other hand, clean energy solutions can stimulate business opportunities and job creation. And all proposed technologies must also be examined as to their health and safety, and environmental impacts, and the economic feasibility and benefits. Life cycle analyses can help separate those technologies that are “no-regrets” – and can be invested in today – from those that require further study.

With the proper financial incentives and the dismantling of ‘perverse' ones, the clean energy and technology transition can improve public health, help stabilize the climate and become the engine of economic growth and poverty alleviation in this 21st Century.