A large part of disruptive climate change is the water crisis. We feel its impacts through worsening floods, rising sea levels, shrinking ice fields, droughts, desertification, shrinking arable land, forced migration of large numbers of people and uncontrolled fires. An appalling example is the extensive fires during January 2025 in the Los Angeles area, largely due to a drying out of the area. Rapidly rising insurance premiums or no insurance availability are contributing factors to the misery of those living in disaster-prone areas.

By 2050 the United Nations estimates that global sea levels will rise by an average of one foot above 2000 sea levels even if carbon emissions are substantially reduced. By 2100 it is estimated that average sea levels will rise between two and seven feet. As many as 180 million people worldwide will lose their homes, and coastal U.S. cities such as Miami, New Orleans and New York will endure severe damage. The exodus of afflicted populations will lead to severe economic and political conflict. Water related issues also generate serious health threats. The World Health Organization estimates that between 2030 and 2050 worldwide climate change will cause about 250,000 additional deaths each year from water-related causes such as malnutrition, malaria, diarrhea and heat stress. By 2100 climate change could cause over three million additional deaths annually.

Climate change has a strong effect on water resources in Colorado. It effects snowpack, stream flow, soil moisture and total evaporation. Colorado’s average temperature increased by an average of 2.3 degrees Fahrenheit between 1980 and 2022. It is estimated that the average Colorado temperature will increase by another 1-4 degrees Fahrenheit by 2050. Warming has led to a greater than 10% decrease in runoff to the Colorado River Basin. The loss of water in the Basin equals the entire water volume of Lake Mead. Warming also devastates Colorado’s spring snowpack, which could be reduced by as much as 30% by 2050. Colorado River flows have declined by about 20% over the last century and may decline by another 30% by 2050.

Groundwater depletion also threatens Colorado agriculture. For example, the Ogallala Aquifer, which supports much regional agriculture, has dropped significantly. The scarcity of groundwater compels a shift to less productive and less profitable dryland farming. Water intensive crops, like alfalfa, dominate Colorado agriculture. Groundwater depletion makes maintaining these crops increasingly difficult. Agricultural problems in Arizona and the southwest will have national consequences, including increased dependence on food imports (assuming these are available). They will also lead to rural depopulation.

The relation between water and climate change has local consequences in Boulder. The city’s water supply depends heavily on snowmelt in the mountains to the west. Climate change has increased the risk of drought in Boulder. The St. Vrain watershed, which includes Boulder, has experienced drought conditions in 55% of the weeks since 2000. Population growth will increase water demand and could render drinkable water supplies inadequate. Drought conditions also increase the likelihood of fires to which Boulder is prone.

Although the interaction between water and climate change requires grave concern, the situation is by no means hopeless. The impact of climate change can be mitigated by sharp reductions in the use of fossil fuels. Water conservation, reuse and recycling can be promoted. Water management practices can be improved worldwide including in Boulder. Water can be transferred from agricultural to urban use when necessary. Reforestation using resilient tree species can improve watershed conditions. More efficient irrigation systems can be deployed and agriculture can transition to crops requiring less water. Natural water systems such as wetlands and forests that function as carbon sinks can be protected and restored. Groundwater extraction and use can be regulated to increase sustainability.

But the greatest single requirement is the political determination to address climate change and our water crisis in a bold, comprehensive and international manner.

John Balassa lives in Boulder.