The most compelling climate change evidence scientists have of climate change is long term data relating atmospheric CO2 levels and global temperature, sea level, the expanse of ice, the fossil record and the distribution of species.
This data, which goes back millions of years, shows a strong correlation between CO2 levels and temperature. Recent data shows a trend of increasing temperature and rising CO2 levels beginning in the early 19th century.
Because all parts of the global climate are connected, scientists have been able to create models of how changes caused by heating should work their way through the entire system and appear in different areas, for example, sea level, intemperate weather, the movement of fish species in the ocean.
Testing whether or not predicted changes have occurred is an important way to verify underlying theory.
This can be done in two ways.
First, it is possible to load a model with historical data and ask: how well does this model predict what we know happened?
NASA and other scientific agencies have done this and found that the models work well.
A second way to test is to use the model to predict upcoming changes and then to see if emerging reality fits. It is possible to track the rapid retreat of glaciers and observe the summer melting of the Polar Ice Cap. Sea levels are rising measurably, the temperature of the world’s oceans is demonstrably rising and consequently many fish species are moving to follow waters that are the right temperature for them.
Correlating these changes to the timing of rises in CO2 levels and temperature suggests relationship. NASA provides a good visual tool for viewing these relational models “in action”.
In specific instances, for example, CO2 levels, temperature and ocean pH, the chemical processes are traceable proving direct causal connection.
Visual Impacts of Climate Change Evidence
Rising Sea Levels