Climate Change - How Much?
Average global temperature has increased about 1.4 degrees Fahrenheit compared with what it would be without people.
Why does this apparently small change matter?
- Warmer oceans drive more hurricanes and more fierce hurricanes.
- Expands the oceans - sea level rise
- Melts polar ice, glaciers - sea level rise
- Moves all living things northwards
- Temperature changes become more extreme
- More air conditioning, more intolerable hot regions
Why should we believe that?
- Satellite sensing has revolutionized the accuracy and extent of the measurement of global changes
- Measuring sea level, average surface temperature, desertification, ice area, glacial retreat, deforestation, ...
- There is more data, more accurate data, more convincing data consistent with models.
- Loss of ice the most obvious
Secondary Nasty Effects - Disasters
- Severe Fires - 2020 Western US, Australia
- Hurricanes & Typhoons - Lots 2020
- Floods - 2020 many worldwide - Once in a generation is now every few years.
- Droughts - many 2020 - the slow disasters
- Reef deaths
Modeling - Verifying and Predicting Climate Change
- Climate change is a complex issue with complex modeling.
- The most important (but not only) aspect of climate change is global warming caused by CO2 increases.
- CO2 atmospheric concentrations over the last few hundred years current levels are far above historic levels
- CO2 has increased in lockstep with the expansion of the use of fossil fuels.
Is the modeling correct?
- So far it seems to be correct
- Big question - is global warming unstable? Could it accelerate for some reasion?
- Hard to predict - see How Fast
Last updated: September 2020