1. **Surge in CO2 Levels:** Since the industrial revolution, there has been a rapid increase in carbon dioxide (CO2) levels in the atmosphere, reaching levels not seen for at least 800,000 years. This aligns with the widespread burning of fossil fuels, releasing CO2 previously trapped underground.
2. **Ocean Warming:** More than 90% of the extra heat trapped by increased greenhouse gases is absorbed by the oceans. Over the past few decades, there has been a significant increase in ocean temperatures, indicating an energy imbalance linked to rising greenhouse gas concentrations.
3. **Aerosol Cooling Effects:** Human activities release aerosol particles that block incoming solar radiation, partly offsetting the warming caused by greenhouse gases. Accounting for these cooling effects reveals that human-released greenhouse gases have an even more significant warming impact.
4. **Consistent Trends with Human Factors:** Long-term temperature trends closely align with known human-induced factors. The patterns of temperature change over the last century match expectations based on our understanding of how increased CO2 and other greenhouse gases affect the climate, surpassing what natural factors alone can explain.
5. **Glacier Melting:** Glaciers outside the polar regions are rapidly retreating, and this accelerated melting corresponds with the increase in greenhouse gases. While natural factors influence glaciers, they fall short in explaining the recent and drastic melting observed.
In summary, various pieces of evidence strongly indicate that human activities, particularly the release of greenhouse gases, are the primary drivers of recent climate change. Climate models that consider human influences align more closely with observed warming trends.
