Climate Warming Tipping Point
We’ve all heard about global warming. The earth’s warming, it’s not — it’s cooling. One thing’s for sure, my head is spinning. It’s gotten hard to keep track of what kind of climate change we’re really in for. James White, Professor of Geological Sciences, Univ. of Colorado at Boulder, talked with me about what he thinks may be a tipping point.
Prof. White says that we may be in for an abrupt climate change, which is when the climate system shifts modes very rapidly (in a few years), by large amounts (5 to 10 degrees C annual temperature, doubling or halving of precipitation, etc.). This type of change is particularly scary, as it is unpredictable and potentially devastating.
The timing of thresholds are hard to predict. Arctic sea ice extents dropped dramatically this past year, for example. Models can predict that change, but not the exact timing.
Is there anything we can do to prepare for abrupt climate change?
The amount of carbon dioxide (CO2) in the air has a direct affect on the amount of warming our planet experiences.
- At 380 ppm CO2, we are 100 ppm above the preindustrial level.
- 100 ppm is the difference we see in ice cores over the past 1 million years between glacial periods and interglacial periods.
- The climate system has inherent inertia, and thus most of the response to this increase in greenhouse gases is yet to come.
- Increased levels of greenhouse gases will change climate. This is simple physics, and not a matter of scientific debate.
- Quantifying feedbacks are key to understanding our future. Small changes in greenhouse gases can cause warming that trigger sea ice melt that in turn trigger much more warming as blue water replaces reflective, white ice.
- Climate change from greenhouse gases is only one measure of human impacts on the planet. We make as much nitrogen fertilizer as all bacteria in the world.
- We produce as much sulfate (a cooling aerosol that is a major cloud condensing nucleus) as all phytoplankton in the ocean.
- We have power, we have the domination we’ve long sought… but now we need to accept the responsibility that comes with that power. Its time to mature and start doing that.
Have we already exceeded a level of increased greenhouse gases that will ultimately result in large increases in sea level (many meters), rainfall patterns, temperatures, and other parts of the climate system? The past would tell us yes.James White – A biography
James has started the INSTAAR Stable Isotope Lab in 1989. In recent years, his research has helped to show that large climate changes tend to occur in the natural system as abrupt and rapid shifts in mode probably driven by internal adjustments in the Earth climate system, rather than slow and gradual adjustments to changing external conditions, such as the amount of energy received from the sun.
His research has also helped to show that land plants are capable of removing large amounts of carbon dioxide from the atmosphere, amounts that equal our input of CO2 from fossil fuel burning on short time scales. Such large changes in the uptake of CO2 by plants is a key piece in the puzzle we must solve to address future CO2 levels and climate change.
James has written following research papers and also been a contributor of number of publications
- Global scale climate and environmental dynamics.
- Carbon dioxide concentrations and climate from stable hydrogen isotopes peats and other organics.
- Climate from deuterium excess and hydrogen isotopes in ice cores.
- Isotopes in general circulation models.
- Modern carbon cycle dynamics via isotopes of carbon dioxide and methane.