Earth is Warming Faster Than Ever. But Why?

Source: Slashdot

Accelerating Global Warming

“Global temperatures have been rising for decades,” reports the Washington Post. “But many scientists say it’s now happening faster than ever before.”

According to a Washington Post analysis, the fastest warming rate on record occurred in the last 30 years. The analysis used a NASA dataset of global average surface temperatures from 1880 to 2025 (GISTEMP). Robert Rohde, chief scientist at Berkeley Earth, noted, “We’re not continuing on the same path we had before. Something has changed….” Temperatures over the past decade have increased by roughly 0.27 °C per decade, a 42 % rise.

The Role of Aerosols

For decades, a portion of greenhouse‑gas‑driven warming was masked by sulfate aerosols. These particles, while harmful to human health, reflect sunlight and have offset about 0.5 °C of warming globally.

Starting around two decades ago, many countries reduced aerosol emissions, especially sulfate aerosols, by:

• Tightening air‑quality regulations.
• Shifting from coal and oil to wind and solar power.
• Cutting sulfur dioxide emissions by ~40 % since the mid‑2000s (with an even larger decline in China).

A recent international regulation also slashed sulfur emissions from ships by about 85 % (Washington Post article). This reduction has lessened the cooling effect of aerosols, contributing to the recent acceleration in warming.

Cloud Feedbacks

Some researchers argue that aerosol reductions alone cannot explain the record heat of the past few years. In a 2024 Science paper (link), scientists estimated that about 0.2 °C of 2023’s record heat (≈13 %) is attributable to a decrease in low‑lying cloud cover.

Low‑lying clouds reflect solar radiation; their reduction allows more sunlight to reach the surface, amplifying warming. The decline in cloud cover could be:

• Partly linked to reduced aerosol particles, which serve as cloud condensation nuclei.
• A feedback loop where higher temperatures make it harder for low‑lying clouds to form.

Implications for Future Warming

• If aerosol reductions dominate the acceleration, the warming rate would likely plateau once aerosol emissions reach near‑zero, returning to a slower, pre‑acceleration trend.
• If cloud feedbacks are the primary driver, the acceleration may continue, leading to more intense heatwaves, storms, and droughts.

The Washington Post’s original headline captured the surprise: “Scientists thought they understood global warming. Then the past three years happened.”

Recent Extreme Events

• Nuuk, Greenland recorded temperatures over 20 °F above average.
• Parts of Australia experienced temperatures exceeding 120 °F during a record heatwave.