|
Weather is the day to day temp, humidity and wind. Climate is the average weather over a long period of time. We cannot predict the weather precisely, but we absolutely can predict that climate. If you live in Arizona, it's going to be hot 8 months of the year. The winter will be cool and you'll have a monsoon somwhere between June and August. Global climate mostly refers to the global average temperature.
Climate change models consider the sources and sinks of greenhouse gas emissions. Neglecting human interference and rare catastrophic events (like a HUGE volcano eruption) greenhouse gas concentrations are relatively static because the emissions are consumed by biogenic sinks.
Now, our industrialization adds a LOT of greenhouse gasses to the system. There are no sinks for the additional emissions and as a result CO2 levels rise. Normally, most radiant energy is reflected back into space. Greenhouse gasses aborb the energy and allow more heat to be trapped in the atmosphere. We have sampled ice cores and determined historic CO2 levels we can line them up with known sea levels at those times and we know that when CO2 levels are low, there is more land mass and the climate is cooler. At high CO2 levels, the climate is hotter and we have less land mass because the ice caps have melted.
These are facts that cannot be disputed. THe arguements (logical ones at least) are with the models, and hte projections built into the models.
|