Climate Change Explained: Is Earth Becoming Too Hot for Human Habitation?

The continuous burning of carbon is causing our planet to experience ever-increasing temperatures.

A 12-year-old from Boise, Idaho named Joseph asked about his parents' concern that climate change is making Earth too hot for human habitation. This raises important questions about our planet's future.

While many regions have experienced extreme heat recently, most inhabited areas won't become completely uninhabitable, particularly in drier climates where the body can effectively cool itself through sweating.

In dry environments, our bodies naturally regulate temperature as sweat evaporates from our skin, releasing heat. However, this cooling mechanism becomes less effective in humid conditions.

The most dangerous situations arise in regions like the Middle East, Pakistan, and India, where scorching desert heat combines with humidity from nearby oceans. For hundreds of millions living in these areas, often without air conditioning, this combination poses severe health risks.

Climate scientists utilize "wet bulb thermometer" measurements to assess these dangers. When wet bulb temperatures exceed 95°F (35°C), the human body struggles to dissipate heat, potentially leading to fatal consequences during prolonged exposure.

The 2023 heat wave in the Mississippi Valley approached concerning wet bulb levels. More recently in May 2024, Delhi, India experienced temperatures exceeding 120°F (49°C) for several days, resulting in multiple suspected heatstroke fatalities as wet bulb temperatures neared dangerous thresholds.

The root cause of these changing conditions is carbon dioxide accumulation. When we burn carbon-based fuels—whether coal in power plants or gasoline in vehicles—CO₂ builds up in our atmosphere, trapping solar heat near Earth's surface. This phenomenon defines climate change.

Every instance of fossil fuel combustion contributes incrementally to global temperature increases. As a result, dangerously hot and humid conditions are expanding to previously unaffected regions.

Parts of Louisiana and Texas along the Gulf Coast face growing risks of hazardous heat-humidity combinations. Similarly vulnerable are irrigated areas in the Southwest where agricultural water usage increases atmospheric moisture.

Beyond uncomfortable weather, climate change triggers cascading problems. Higher temperatures accelerate water evaporation, drying out vegetation and increasing wildfire susceptibility—each Celsius degree of warming can increase western U.S. wildfire risk sixfold.

Ocean warming causes water expansion and rising sea levels, potentially displacing up to 2 billion people by 2100. These combined impacts threaten the global economy, with continued fossil fuel use potentially reducing global income by approximately 25% before century's end.

The situation presents both challenges and opportunities. While continued carbon burning will inevitably lead to further temperature increases, we have viable alternatives in clean energy technologies like solar and wind power.

Significant advancements over the past 15 years have made renewable energy more reliable and affordable. Nearly all nations worldwide have committed to halting climate change before irreversible damage occurs.

Just as previous generations improved living conditions through technological advancement, our transition from fossil fuels to clean energy represents a necessary evolution to maintain Earth's habitability for future generations.

(Author: Scott Denning, Professor of Atmospheric Science, Colorado State University.)

(This article is republished from The Conversation under a Creative Commons license. Read the original article.)