Global Climate Change – Population Matters-USA

Used with permission of the artist, Bilicki, via CartoonStock

You have probably observed some changes recently. It’s hotter and dryer, there are fewer birds and it seems that more young people seem to be getting cancer.

These are all symptoms of a sick environment. Climate chaos is caused by greenhouse gas emissions—primarily CO₂ from burning fossil fuels. The numbers of birds and other wildlife are plummeting or going extinct. This decrease in nonhuman species has multiple causes, including climate chaos, loss of habitat and environmental poisons. We humans also are tragically affected by environmental toxins, of course. For instance, a recent study found 920 chemicals in our food, water and air that have been associated with increasing the risk of breast cancer.

Scientists have developed the chemicals and many things that are responsible for these adverse changes. Now, however, some scientists are warning us how serious our situation is, and making suggestions how to prevent worse disasters.

The “World Scientists’ Warning to Humanity: A Third Notice” will be published in 2027. The first Scientists’ Warning was published in 1992, followed by a second Warning in 2017. That one holds the record for the number of cosigners for an article—15,364!

The second Warning listed six changes that we need to make, including “…stabilizing and gradually reducing the population by providing voluntary family planning.”

The third Warning also lists six “transformations to stabilize the Earth system.” In summary, they are: Energy-stop burning fossil fuels; Nature-protect and restore; Economy-align with planetary limits; Consumption-decrease overconsumption; Food-eat less meat; Social Justice-universal access to health care, housing and education, especially for women. It is regrettable that any mention of human population is omitted.

There is a whole “Scientists’ Warning” series of articles, including “Scientists’ Warning on Population” and “Why Do Society and Academia Ignore the ‘Scientists Warning to Humanity On Population?”

Two physicians, one British and the other Czech, have encouraged people to think about the environmental impact of humans in their article, “Doctors and overpopulation 48 years later: a second notice”. In addition, Dr. Greguš recently published “Scientists’ warning: Population as a threat to security.” He states, and I agree, “Security is achievable, however, if governments make rational choices to reduce population via embracing reproductive ethics of small(er) families and provide affordable access to contraception to all those who ask for it.” Security is threatened because overpopulation has caused climate chaos, environmental degradation and forced migration, amongst other problems.

The third Warning is not perfect. Nevertheless, I joined the thousands of scientists who have already signed it. A draft is available at: https://scientistswarning.forestry.oregonstate.edu/sites/default/files/Third_Notice.pdf . If you would like to sign your support, here’s the link: https://forms.gle/BAfifGWesmoYjKzi7

If you don’t consider yourself a scientist, you can still express your concern. Please sign the “Public Endorsement: Declaration of a Planetary Emergency”. It “…recognizes that humanity faces a planetary emergency and calls for urgent, coordinated action to protect the natural systems that sustain life while advancing human well-being and a livable future.” You can access it at: https://docs.google.com/forms/d/e/1FAIpQLSdlPKM-SC5BiieIX7waPauyVsZuuA0BNsCMCq96sJxeXdlZlQ/viewform .

There is another, very important action you should take, whether or not you are a scientist—vote! If you are a registered voter in the USA, please vote in the November election. When you vote, consider the candidates’ platforms. Will they help or worsen the state of our planet? Because voluntary slowing of human population growth is vital to our planet’s health, where do the candidates stand on reproductive health issues?

©Richard Grossman MD, 2026

Postscript to Heed this Warning!

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If you are reading this, you are probably one of the majority of people worldwide who share a concern about the state of our world. My thanks to Dr. Ripple and thousands of other scientists who have publicized the problems we are living with—and which we have all contributed to. Overconsumption and overpopulation are the two major factors that cause our impact to be unsustainable.
Some people focus on the outlandish consumption in rich countries. Indeed, we have more than we need to live good lives. Furthermore, paradoxically the consequences of our overconsumption affect less well off people much more than us.

I am tempted to ask those who focus on consumption about the size of their footprint.

Other people focus on slowing, then reversing, human population growth; I am in this camp. My belief is that voluntary family planning is the least expensive, most effective and most humane way to improve our environmental impact. Unfortunately, family planning will only work to decrease impact in the longterm.

What is your personal footprint? Unless you are aware of how much you contribute to this global problem, there is not much you can do about it.

There are many measures of a person’s impact: Ecological Footprint, carbon footprint, water footprint etc. In addition, there are multiple digital applications to help you determine yours, but I haven’t found one that I would consider top notch.

I checked my carbon footprint for this past year using the US Environmental Protection Agency app. It was good because it was simple, however it left out diet and flying. Because of several trips this year, my footprint is large. The average for a US citizen is about 20 tons of CO₂ emitted on their behalf. What have I done to reduce my impact?

I have already increased my plant-based food intake, and get most of our energy from the sun. At age 83, with a love of travel, I hope to continue flying a few more years. Fortunately I have found an excellent way to mitigate the carbon emissions which I cannot, nor wish to, reduce further.

There is a difference between “mitigate” and “offset”. To mitigate is to reduce the harm at the site of the harm, while offsetting is attempting to reduce harm by an action elsewhere. Unfortunately, offsets are often difficult to monitor and many offset scams have been reported.

My wife and I have lived in a cohousing community since 2000. This way of life is more efficient than the usual solitary home because we are surrounded with friends and because we share some common facilities. For instance, we have a shared workshop so I don’t need one in my basement. Our home is quite efficient, resulting in smaller than average utility bills. The 14 new Heartwood Phase 2 homes are constructed to be even more efficient than ours, with amazing insulation and all electric heating and cooling.

Several years ago Heartwood started the voluntary “Renewable Energy Fund”. We have used it to mitigate the use of fossil fuels in our community. We now have a large solar array that supplies most of the power for the workshop, our Common House and an electric vehicle charger. I contribute an amount in order to mitigate the impact of our trips to this fund.

Whatever you do—or don’t do—to offset or mitigate your carbon emissions, please keep in mind that we need politicians who are good caretakers of our environment. Furthermore, please keep this in mind when you which candidates to vote for!

Trees killed by drought and spruce beetles on Wolf Creek Pass

It is windy, hot and dry, dry, dry here. According to www.drought.gov, Durango is in an extreme drought. What’s going on? Do we need to start doing rain dances?

Past droughts have brought us some pretty destructive fires. Remember the Missionary Ridge and Valley fires in 2002? More recently the 416 fire in 2018 did dreadful things to the local economy and burnt 52,000 acres of forest. Fortunately there were no serious injuries or burnt structures. Thank you, firefighters! Very dry conditions predispose us to wildfires, of course. Even if your property isn’t burnt, we all suffer from the costs of firefighting and many of us from smoke-worsened respiratory problems.

Much of our water supply falls in the winter as snow. Snowfall this past winter started off looking good. However, in March precipitation dwindled so it seemed as though somebody turned off the tap. The cooler-than-average spring helped hold some of the moisture in the mountains, but now the snow has melted. We need the monsoons to bring us rain!

A large area in the southwest of the USA has been affected by drought–but that isn’t anything new for this region. Tree ring records tell us the Ancestral Puebloans (also called “Anasazi”) survived dry periods in the 9^thand 12^th centuries. Finally, after about 1150 it got so dry here they started migrating to the Rio Grande valley, archeologists tell us.

Reality appears more complex, however. The human population grew during the wetter years between droughts. When the megadrought hit in the 1150s, violence erupted, just as it did in Rwanda when people were starving. There were even signs of possible cannibalism in the 12^th century at Cowboy Wash, near Mesa Verde.

What are “megadroughts”? People who study droughts rely on dendrochronology (the study of tree rings) to look at the prehistoric past. A drought lasting 20 years or longer qualifies as a megadrought. Another definition is that it is any drought worse than anything the USA experienced in the 20^th century–including the Dust Bowl. From a sociological standpoint, megadroughts usually cause mass migrations of people. What is unusual is that is that people are migrating toan area of drought. We are so disconnected from the natural world that we can live in comfort with air conditioning and imported food.

The natural variability of weather and climate is thought to be the main cause of megadroughts, but there are at least two other contributing factors that are human caused. An example of a local effect is in Rajasthan, India, where the Thar Desert was once forested. Alexander the Great’s army, amongst others, cut down trees to build ships to cross the Indus River in the 320s, BCE. It is thought that this destruction of forests may have been a factor in this desertification.

Global climate heating has had a much wider effect on our climate than in just one location. It is generally accepted that the climate crisis is anthropogenic, so the more people there are and the more each of us consumes, the worse the heating.

Rajasthan is an example of how cutting down trees can change the local climate. Can planting trees help? The amazing Kenyan woman, Wangari Maathai, started a movement that may help answer the question. The Green Belt Movement she started did much more than just plant 51 million trees; Dr. Maathai used trees as an entry point for community development. Increasing women’s income, justice and reduction of poverty are among the humanitarian goals. The environmental goals are to combat deforestation, provide firewood for cooking and protect the watershed. This quote from a UN report shows success:

“Because of the deforestation, natural springs that fed the Chania River dried up, making the river’s water levels very low. The reforestation efforts of the women in the watershed have led to the rejuvenation of 65 springs. And the microclimate is enhanced in the planted areas: ‘We have noticed more rain since we planted the trees. When I came in 2008, you could walk across the river; now, it is almost back to historic levels’, said Joyce Nyambura, a Green Belt Movement Extension Officer.”

Back to the American Southwest. We are in the midst of a megadrought which started in 2000. It made worse by the increasing number of people and their demand for water almost doubling. A study has looked at the causes of this dryness and found that climate heating is a major factor for our drought. The authors calculated that only half is due to natural variation; the other half of the cause of the scarcity of water is anthropogenic.

It is too late to prevent our current megadrought, but hopefully the natural cycles of nature will bring rain to this parched land. What we can do to protect the next generations—indeed, must do–is to decrease our consumption and slow population growth.