By Lenny Karpman

Ask the wives and husbands of physicians and other scientists if we are fundamentally skeptics. They will shout “YES!” heartily and laugh that you even asked. So when more than 98 percent of us believe that global warming is occurring, and that the billions of tons of CO2, which we are adding to the insulating blanket that keeps heat from escaping our atmosphere, is a major part of the problem, wouldn’t it be prudent to heed our collective warning? 

The telltale signs of global warming are measurable increases in land and ocean temperatures; melting glaciers and ice caps at accelerated rates; migration of plants, animals and vector-borne diseases to higher altitudes and latitudes more distant from the equator; disruption of usual climate patterns with more and longer droughts and areas of unprecedented rain and flooding; plus secondary hurricanes, tornados and wildfires. 

Prior to the industrial revolution, the CO2 blanket atop our atmosphere balanced emissions from the Arctic tundra and decay of plants and animal waste with removal from the atmosphere by oceans and forests. As oceans warm, they absorb less CO2.

Compare the gas that escapes uncapped bottles of carbonated drinks when one is cold and the other is warm. The obvious vicious cycle follows that as global warming causes the oceans to absorb less CO2, and as wild fires, felling trees for pasture land and housing and logging decrease our forests, the planet’s ability to counter the effects of man-made waste from burning fossil fuel is diminished, and global warming begets more global warming. 

Current estimates suggest that we are adding 10 billion tons of CO2 to the atmosphere annually, eight billion from burning fossil fuel and two billion more from deforestation. This total is up four billion tons per year in just the past decade. 

Ample clean water and warm sunshine have blessed our paradise with 5 percent of all the world’s species of plants and insects and as many bird species as all of North America combined. The key is our cloud forest cover. As warm air ascends our mountainsides above 1,000 meters, clouds form and produce life-giving rain. Ask the longtime residents of Monteverde, Poás or Irazú rain forests about their microclimates, and you will hear that the weather is more chaotic, seasons more variable, and that there are more frequent torrential rains and mudslides. There is also progressive warming and drying over decades. 

Naturalists will add that lizards, snakes and birds are entering habitats at higher altitudes than ever before competing for food; that coffee is growing less well at its lowest elevations and is blossoming earlier than ever before at higher elevations; and that an alarming number of plant and animals species are declining or have disappeared.

Dengue was unrecognized here in Costa Rica only a few decades ago. At first it was a lowland disease in areas of stagnant water and high temperatures, mostly on the northwest and Caribbean coasts. It has now ascended all the way into and around San José, home to 40 percent of our population. It is still absent at elevations too high for the Aedes aegypti mosquito to survive, at least for now. 

From 2006 to 2007, the number of reported cases more than doubled despite progressive government education campaigns to eliminate breeding sites for the mosquitoes, which harbor the infectious viruses. 

Two other diseases are worthy of mention: cholera and malaria. Diminutive forms of the cholera bacterium live in warm oceans on chitin. When coastal warming occurs, they enlarge to infectious size and come ashore in seafood and water. When they infect people, human waste can contaminate food and water and cause an epidemic. The diarrhea and dehydration can be deadly if not rapidly recognized and vigorously treated. More than 100,000 people die from the disease each year. 

In the early 1990s, cholera hit a Peruvian coastal town outside Lima during an El Niño time. The disease has never totally been eradicated from the Peruvian coast since. It spread throughout most of Central America and hit Nicaragua hard. We were spared due to vigorous public health screening and treatment along our borders. 

Another El Niño is forming now. Climatologists suggest that as our oceans grow warmer, multiple El Niño phenomena will occur more frequently. The first ever in the Atlantic has recently appeared. 

The Anopheles albimanus mosquito can carry the parasites that cause different types of malaria. To infect humans, mosquitoes need to live long enough for the parasites to mature. When warming occurs, mosquitoes proliferate, live longer and reach higher elevations, and the parasite matures faster. 

In the cantons of Matina and Talamanca in Limon Province, malaria can be a hazard. Fortunately few travelers ever go there. The local strain is chloroquine-sensitive. 

Costa Rica is pursuing a praiseworthy integrated path to achieve carbon neutrality over the next decade. We are admired internationally for doing so. Let us hope that enough other countries follow suit in time to prevent escalating droughts and diseases, diminished supplies of food and drinking water and conditions in other parts of the world similar to East Africa’s famine, Texas’s wildfires, unprecedented floods in the U.S. and rampant cholera in Haiti. 

As individuals we must be heard to counter the claims of the vocal minority who would have us do nothing. Help educate the sincere good people who are sadly misinformed and stand up against those who would further endanger our planet because of political demagoguery or a greed-driven wish to remove all controls on all capital profits at any price.

Lenny Karpman is a nine-year resident of Costa Rica, a retired cardiologist, author of several books and articles on food, travel, medicine and human rights.