Are human CO2 emissions driving current global warming?

While many natural factors influence Earth’s climate, human emissions of heat-trapping carbon dioxide are driving today’s global warming.

Scientists have conducted detailed studies of climate “forcings,” or the factors impacting global temperatures, especially with the past 50 years of satellite data. Long-term natural forcings, such as changes in Earth’s orbit or tectonic movement, take tens of thousands of years. They cannot explain the pace of recent warming.

More immediate, smaller-impact changes occur in shorter-term cycles and cancel out over time. Solar cycles and weather patterns such as El Nino and El Nina manifest as irregular oscillations in temperature graphs.

In contrast, human CO2 emissions have increased by 50% in less than 200 years, from 290 ppm to 430 ppm. Today’s global temperatures are 1.5°C (2.6°F) warmer than the pre-industrial average. The long-term upward trend in today’s temperatures can only be explained by the concurrent human-caused rise in atmospheric CO2.