The Intergovernmental Panel on Climate Change has given a devastating warning about human-made contributions to global warming. As health professionals who care for our communities, we feel compelled to sound the alarm when public health is in danger.

On this Earth Day, we encourage everyone to consider the devastating impacts of climate change on our health and make an effort to take action.

Scientists around the world are overwhelmingly convinced that the Earth's climate is rapidly changing because of human activities. As we burn fossil fuels - coal, oil, methane gas - for power, we systematically add increasing amounts of heat-trapping gases to the atmosphere. This results in increasing global temperatures, extreme weather events, and escalation of harm to human health.

Because of our reliance on and pursuit of fossil fuels, our air and water are compromised, our food supply is threatened, and infectious disease is spreading. Here in Southeastern Pennsylvania, the breeding season of West Nile Virus increases, children who play outdoors develop asthma, and our cities become heat islands, killing those with existing heart conditions and lung disease.

In Pennsylvania, we have hundreds of coal mines, nuclear power, and coal-fired power plants, and more than 7,000 natural-gas wells extract methane - a more potent greenhouse gas than carbon dioxide. Pennsylvania is second in the nation in producing greenhouse-gas emissions from power plants and refineries, and the state singlehandedly produces 1 percent of the world's greenhouse gases. As a result, the fossil-fuel industry is not only putting the health of our communities in danger, but it is exporting illness to the rest of the United States and, ultimately, to the rest of the world. As public-health advocates, we cannot and must not remain silent.

Health - of people, of animals and livestock, and of our natural environment - can no longer take a backseat.

Children, the poor, the elderly, and those with weak or impaired immune systems are especially vulnerable and are frequent victims of these extreme methods of fossil-fuel extraction. So too are the industry's working class, who, while fortunate to have jobs, have had their health put at risk.

Unknown scores of people living and working in affected communities are plagued by lung cancer, low birth weight, heart attacks, and other effects of chemical poisonings, and should not continue to be harmed.

Safe and sustainable jobs and a safe environment must be a priority at every level, rather than workers and nearby residents paying the price so everyone else can enjoy inexpensive energy.

If we continue our current course, not only will the resulting burden exceed the capacities of modern medicine, but everyone - that is, all of humanity - will pay the price in terms of the effects on our environment. We will leave for our children a fatal legacy of natural disasters, epidemic disease, and violent conflict over shrinking resources.

Pollution of our air and water and a disregard for human health should not and cannot be the cost of doing business in our region.

It is up to us, as concerned citizens, to tell our representatives this is unacceptable. We must:

Demand they act to set firm and more stringent greenhouse-gas reduction goals;

Support them in standing up against fracking as well as coal and tar sands exports; and

Encourage them to oppose mining and drilling on public lands.

The only candidates for office who are worthy of our votes are those who vigorously support these objectives and who steadfastly seek to protect health and our environment.

In our own homes, too, we can make the switch to renewable energy, which, in addition to inhibiting grave harm to our environment and health, creates long-lasting jobs for those in our community. It is our responsibility as stewards of the Earth to not only seek a gradual reduction of our own footprint, but to strive for bigger gains that eventually change our community and our world.

For too long, public health has been ignored as we pursue and demand ever-increasing supplies of energy. These practices are laying the groundwork for irreversible damage to health - of individual people, of our community, and of our planet.

On this Earth Day, we urge you to take one action: Call your state and local representatives, as well as those running for office, and ask them to advance legislation that will cut our fossil fuel use in half by 2030.

Together, we really can make a difference and enjoy the promise of a hopeful and healthier future.