Climate change is a complicated concept. Although the science behind the climate change predictive models and the projections is complicated, the basic tenets of what is happening are relatively straightforward. Man’s continual, rapacious thirst for cheap sources of energy has produced gases that have gone into the atmosphere and act as a sort of  barrier preventing the earth’s heat from dissipating. The end result (and I do mean END), is that the earth’s atmosphere is gradually warming and that process of warming is accelerating. The worldwide scientific community agrees that this is happening and that the consequences for the earth, all species, and man are dire.

One of the main factors underpinning the difficulty of the public in understanding climate change is the comprehensive campaign of lies and deceit promulgated on this subject by the fossil fuel industry. That particular sin against humanity is not the focus of this essay, but it is important to know that it continues and is highly effective.

One analogy that I have used in past speeches is to consider climate change as a major hurricane approaching a community. All the scientists have read their instruments and radar and are projecting with 99% certainty that the storm will come ashore right at their location. There’s no time to lose. However, the elected representatives (in the US, these are Republicans) are telling the public that there is no cause for alarm and that the public should continue to boat and swim. They claim loudly, “I’m not a scientist, but this storm isn’t real.” If you look at the last 5 years, though, to continue this analogy, the winds have picked up and there are dark clouds on the horizon. It’s coming, Auntie Em. It’s coming.

I guess I need to establish my bona fides on this subject. I was CDC’s point scientist on climate change for over a decade. I was co-chair of the health sector for the First Nation Assessment of Climate Change and a lead author for the Second Assessment. I was also a member of the FACA group that conducted the Third National Assessment. I have written extensively and spoken around the country and the world on the health impacts of climate change. I am, fortunately or unfortunately, deeply steeped in this subject.

So, what should we expect as the climate changes? The two main meteorologic impacts will be changes in precipitation worldwide with the greatest concern being extreme events – major prolonged droughts and intense rainfall leading to flooding. We are seeing these precipitation impacts already – in Africa, in Bangladesh, in Australia. The other main outcome of climate change is an overall increase in temperature (the 10 hottest years recorded history have occurred in the last 11 years) with an alarming increase in the number of extreme-heat days and heat waves. It’s not just that the global temperature will rise about 2 degrees C. It’s that the number of heat waves will triple in the next 30 years. For example, the city of Houston now has an average of about 7 days per year when the temperature reaches 100 degrees or more. By 2050, Houston is projected to experience about one month (27 days) each summer of 100 degrees or more. It is going to be hot for more time each summer and the hot is going to be hotter than we’ve experienced. And 2050 is not that far away.

Also, climate change will cause sea levels to rise. This is also already occurring. Over the next 50 years, displacement and disruption of lives in coastal areas will impact hundreds of millions of people.

The health effects of climate change will be many and varied. Obviously, more people will die and become ill from extreme heat. Currently, approximately 650 people die each year directly from extreme heat in the US. Some models project these deaths to increase 8-10 fold over the next 50 years. Cardiovascular and respiratory deaths associated with urban air pollution will increase. The geographic distribution of endemic vector-bourne diseases will be altered.  Malaria, and other mosquito-carried diseases, will move into higher elevations and spread into populations with no developed immunity. As nighttime temperatures warm, the range of tick-borne illnesses, such as lyme disease, will be extended. Food production worldwide will be disrupted leading to even more starvation of large populations than we are seeing now (not that we care about it now). The scarcity of food and potable water will lead to armed conflict and wars. Large areas of flooding will lead to increases in drownings, injuries, and the spread of infectious disease, both domestically and globally. These are just some of the health impacts from climate change.

These outcomes will happen and they will be dramatic. From a public health standpoint, the news is even worse. Globally, the poorest countries will suffer the most. Within each country, the poorest people will suffer the most. Unless some aspects of this tragedy are fundamentally altered, the poorest people in the poorest countries will die. There will be no resources for the adaptations that might save them. In the triaging that will accompany climate change in a few decades, they will be expendable. There is no way in my view of the world that human beings can ever be considered as expendable, but I see that scenario as a distinct probability.

Is the news all bleak? Not at all. Most countries have realized the scope of this problem and are working to mitigate climate change’s effects and adapt for the future. Great strides have been made in cleaner sources of energy with solar and wind power becoming more economically feasible every year. The Swedish car company, Volvo, just announced that they are beginning to phase out gasoline engine automobiles and will soon have an all-electric fleet. Cities across the US and other developed countries are leading the way in adopting adaptation policies to protect their citizens from climate change impacts. Sustainability has gone from being a buzz-word to being a driving force in building, community, and product design.

There is hope, but there really is not that much time. Even if the whole world was to immediately cut fossil fuel consumption to the recommended levels of the Paris Agreement, the impacts of climate change would still be on the horizon. Each country, including the US, needs to adequately address the adaptations that will be necessary to safeguard their population from the impacts of climate change. Alternate energy sources must be developed and marketed to mitigate future climate impacts by eliminating the production of greenhouse gases. Rich countries, who have foisted this problem onto the world, must agree to assist developing countries in adapting to climate change impacts.

Finally, the US must take a leadership role in all of these activities. More than any other country, the United States is responsible for climate change. We set a standard of energy consumption and natural resources waste that no other nation could ever achieve. We led the way to causing this problem and we need to lead the way towards the solutions. As a country, we have the technologic and scientific capability to help solve this mess, but we don’t seem to have the will.