Statement, Tutorial
How scientists calculate climate change
- Climate models simulate future scenarios, such as a world with double current carbon dioxide levels, to illustrate likely 21st-century greenhouse warming, while weather forecasting focuses on predicting events over the next few days.
- Model accuracy varies based on implementation details, with some simulating stacks of 85 cells, grids covering hundreds of kilometres, or running slightly hot or cold due to rules of thumb used for small-scale cloud formation processes that cannot be modeled precisely.
- Historical data indicates that actual warming from the 1970s to the 2000s fell within the error bars of most models, suggesting reasonable reliability, though full representation of Earth's intricate processes remains a work in progress.
- Current emissions reduction trajectories are insufficient to assure staying below 2°C or even 1.5°C above pre-industrial levels, requiring tough climate policies to achieve Paris Agreement temperature targets.
- Models cannot predict specific future human actions, such as a country ceasing carbon emissions by 2050, and the ultimate solution to climate change depends on human choices rather than the models themselves.