Chapter 30: Global Climate Change Flashcards
Climate refers to?
- time and space patterns of precipitation, temperature and wind
Climate change occurs when?
- the patterns change i time (winter months get warmer) and space (monsoon rains occur further south)
Why should we care about climate change? What does climate affect?
- type and location of agricultural farmlands
- weathering of rock, type and rate of soil formation
- quantity and quality of water available for human use
- severity of droughts, storms and floods
- geographic ranges of species, and species interactions
- when temperature changes things will move. It happens too quickly it could be catastrophic bc they cannot move quick enough. Some environments may have are lady reached their peak temps and cannot handle further stress
How do we study climate?
- air bubbles in ice cores retin atmospheric gases present when the ice was formed
- annual tree rings not only indicate tree age, the ring width inmates growth spurts due to warmer temperature
- CO2 measured continuously at Mauna Loa Observatory since 1958 has provided strong evidence for atmospheric change
- peat bogs are also looked at. Record of 1,000 years of the spores … you can reconstruct the community composition
At what rate have global surface temperatures changed over the last 30 years?
huge change in temperature 50’s up..before hand it was fairly constant
- 0.02 C per year
At what rate did global temperature change during the warming period following major ice ages?
- Although the scale of temp change is much larger than has occurred in the last 30 years, the avg rate of warming moving from a glacial to an interglacial period is an order of magnitude less. Trends are showing that its not really coming down..in the old days it would fluctuate up and down but recently this isn’t really seen.
- 0.0013 C a year over 9700 years
CO2 and energy in the atmosphere:
- earths surface absorbs?
- solar radiation and reradiates it as heat
CO2 and energy in the atmosphere:
- CO2 and other greenhouse gases (GHG) do what?
- reduce rate heat can escape into space
- this causes heat to be trapped = greenhouse gas effect.
- Methane, CO2 builds up and is a filter that heat can get through but cannot get out
CO2 and energy in the atmosphere:
- More GHG =??
- higher global temperature
CO2 and energy in the atmosphere:
- role of CO2 and other GHG?
- has been understood for over a century
Glacial cycles are very large naturally occurring changes in global climate that occurred over hundreds of thousands of years. Why are we worried about rapid climate change now?
- measurements since 1958 are higher than anything that has been recorded previously!
- a lot of people argue it is a natural fluctuation BUT they are not putting in CO2 changes just temp changes
CO2 and other GHG vary naturally. Why re humans thought to affect GHG and thus climate?
- human activities including land use change (agriculture, deforestation), fossil fuel use (coal, oil, natural gas) and cement production are known to release CO2 and other GHG.
Other aspects of climate change?
- changes i sea level, sea ice and storms
- also changes in ocean pH
- if water current shut down things will get colder in one place…
Public View about climate change:
-is there scientific consensus?
- yes
- consensus that anthropogenically induced climate change is HAPPENING
Public View about climate change:
- 2011 poll by Yale on Climate change showed what about the public?
- they don’t realize human induced climate change is happening
- 13% Americans answered that (7% climate scientists believe climate change is happening. 33% said they were not sure how climate scientists feel about global warming.
