1. There is warming in the pipeline, like it or not. Today lies far outside the cluster of data points from the Vostok core. Those points represent a rough historical relationship between temperature presuming the climate is at equilibrium. Right now, we are experiencing what climate modelers call the transient response to CO2 forcing. If CO2 concentrations froze now, global temperatures would continue to rise until the climate reached equilibrium.Among recently reported findings that may point to yet further large-scale changes are: Trees absorbing less CO2 as world warms and Melting ice may not explain warming Arctic.
2. That equilibrium point lies outside any experience the planet has had in the past 420,000 years, even without any future increase in greenhouse gas concentrations (as the current CO2 level is unprecedented). A further increase places the planet in an even farther outside the envelope of anything in the "recent" geological record, to use a geologists warped definition of the word recent.
3. Oceanic ecosystems - particularly coral reefs - that are sensitive to both the physical (temperature) conditions and the chemical (pCO2) conditions are already and will continue to experience a thermal and chemical environment not seen for hundreds of thousands of years.
Thursday, January 03, 2008
Simon Donner highlights a figure in a recent paper that uses a simple inversion of the 420,000 year record of temperature and CO2 plots from the Vostok ice cores. He says it "clearly demonstrates three crucial points about the planet's current situation":