Carbon Dioxide

The average level of carbon dioxide in the Earth’s atmosphere had its largest one-year increase on record between 2023 and 2024. In 2024, the level reached 423.9 parts per million, an increase of 3.5 parts per million over the year before. The previous record jump was 3.3 parts per million in 2016. Modern measurements of carbon dioxide levels began in 1957.

To understand climate change, we can look to Venus and Mars, both surrounded by carbon dioxide—the main greenhouse gas. On Venus, CO₂ traps enough heat to keep the surface at 850°F, while on Mars, a much thinner layer still warms the planet by about 40 degrees. Greenhouse gases work by trapping infrared energy: when the Sun heats Earth’s surface, most infrared escapes through simple gases like oxygen and nitrogen, but CO₂ and water vapor absorb and re-radiate it, sending some back toward the ground. This process keeps Earth warmer and explains why cloudy nights are warmer than clear ones—the same physics behind climate change.

Nine Northeastern states are sharing $115 million from the latest auction of the Regional Greenhouse Gas Initiative, which limits power plant carbon…

Less carbon dioxide is polluting the air in the Northeast, prompting state environmental officials to catch up by cutting allowances for emissions in one…