- In the past 100 year global average temperature has risen about 0.6 C
- The cause of natural climate change are not well understood
- factors such as variation in CO2 concentration and variations in the earth’s orbit around the sun are certainly involved
- Climate is the characteristic or average state of the atmosphere for a given region and it refers to the long-term average
- while weather refers to the current state of the atmosphere of short deviations from the mean climate.
- Microclimate is a term that refers to the micro-scale
- the atmosphere around a leaf or the climate within the boundaries of an urban area.
- Climate change is a natural feature of earth.
- Ninety percent of the weight of the atmosphere lies within the first 12 km above the surface,
- consists of nitrogen (78%), oxygen (21%) argon (0.9%), CO2 (0.03%)
- some traces of others such as ozone and methane.
- An atmosphere of pressure is equivalent to 105 N/m2.
- Water vapor content varies from about 1-4%, depending on temperature
- Areas of falling air in the three-cell model produce areas of high pressure
- while areas of rising air produce areas of low pressure
- Ice core data (where we obtain paleo-CO2 trapped in bubbles) shows that Earth’s temperature has varied over time
- Tree rings obtained from logs or cores can show seasonal variability of a climate
- Sediments on land and in water can show patterns of animal and plant growth and allow deduction of the climate conditions
- Coral growth patterns also reflect climate variability
- Carbon-14 is an isotope found in all living creatures, and the rate of its decay can be used to date plant and animal remains
- A greenhouse gas (or GHG) is any one of the gases that absorb long-wave radiation or IR
- GHGs include CO2, CH4, CFCs, N2O, and some others
- The anthropogenic sources of greenhouse gases are increasing as a consequence of industrialization and population growth
- The CO2 is primarily from fossil fuel combustion and secondarily from deforestation
- negative feedback loop, something acts to continue a trend back toward a norm
- positive feedback loop, something acts to continue a trend away from the norm
- Milankovitch cycles involve changes in the Earth’s position relative to the Sun
- The amount of energy reflected by the Earth is called the albedo
- Roughness caused by terrain or by vegetation affects air flow and local weather patterns
- Climate forcing is an imposed perturbation of Earth’s energy balance
- The term forcing is used a lot in the climate change literature, e.g. anthropogenic forcing, meaning caused by people
- vast exchanges of carbon dioxide between the ocean and the atmosphere
- the balance of which determines the extent to which carbon dioxide contributes to the greenhouse effect and global temperature
- El Niño, also know as the El Niňo/Southern Oscillation (ENSO)
- a change in upwelling off the Peru coast that brings widespread climate changes
- such as high rates of precipitation and flooding to Peru, and droughts and fires in Australia and Indonesia
- Adjusting to global warming will take the form of adapting and mitigating