Christoph Schar, Professor at the Institute for Atmospheric and Climate Science, discusses historical heatwaves (including that of 1980 which claimed over 10,000 lives), the variability hypothesis, recent scenarios, land-surface atmosphere coupling, and atmospheric convection.
formerly “Climate Science” this has been updated in recognition of the fact that ALL of our articles, events, etc. involve climate sciience. ”Climate change” is intended to suggest changing elements of the climate: e.g., shifts in global oceanic and atmospheric circulation and ensuing changes to temperature, precipitation, groundwater levels, saltwater intrusion.
The increase in anthropogenic atmospheric carbon dioxide (CO2) alters the atmosphere-ocean equilibrium, changes seawater carbonate chemistry and lowers ocean pH. Ocean acidification is a predictable consequence of rising atmospheric CO2, and lower seawater pH and calcium carbonate (CaCO3) saturation in surface waters have significant implications for the marine organisms.
Global warming simulations suggest that wet regions (where precipitation exceeds evaporation) will become wetter and dry regions drier by the end of the 21st century (e.g., Held and Soden 2006), with larger contrasts expected between dry and wet seasons (Chou et al., 2013). This ‘rich-get-richer’ behavior is consistent with a large increase in the moisture content of atmosphere, leading to enhanced horizontal moisture fluxes across regions.
(CNN) Most of us can appreciate that the world is an ancient place and that a lot has changed in the almost 4.6 billion years since it took its shape.
It’s not easy to have a feel for the amount of time that has passed, but grappling with deep time helps you understand why an atmospheric carbon dioxide concentration (CO2) of 400 parts per million (ppm) is meaningful.
Deep time is geologic time and the scale needed to fathom the evolution of life, mountains, oceans, and Earth’s climate.
Subpolar ocean gyres (large systems of rotating ocean currents) in the Southern Hemisphere are found poleward of the Antarctic Circumpolar Current near the Weddell and Ross Sea. They play a key role in the global energy and water budgets. These gyres are crucial for the transport of heat around the planet, as well as the distribution of nutrients and marine species. Thus, the subpolar gyres are important in the mixing and transformation of water masses.
We are currently on the eve of a world with ~400 parts per million (ppm) of atmospheric carbon dioxide (398.35 ppm as of May 2nd, Mauna Loa Observatory). How global climate, sea-level and ecosystems will respond to this level of CO2 level is a key question for global change research. Recently, Foster and Rohling (2013) looked back into Earth’s geological history to explore the relationship between atmospheric CO2 and global sea-level.
Pearson and colleagues (2013) recently showed how the expansion of shrubs and trees in the Arctic could promote even further warming through a series of positive feedbacks. Their modeling study that estimates the future composition and distribution of vegetation across the Arctic indicated shrubs and trees could expand by as much as 50% over current levels by 2050.
Earth’s climate is characterized by persistent westerly jets (eastward flow) in the upper troposphere, located in the mid-latitudes of the Northern and Southern Hemisphere, which are associated locally with strong weather systems. The location of these jets is of paramount importance to human societies, as these are collocated with maximum in precipitation rates and surface winds in the extratropical regions.
A simple thermodynamic argument suggests that as the water vapor content of the atmosphere increases with global warming dry regions may become drier and wet regions wetter. This enhanced hydrological contrast with global warming can be attributed to changes in the atmospheric water vapor concentration being comparatively larger than those of the moisture advecting winds in the lower atmosphere.
Soils contain two-thirds of the world’s terrestrial carbon (3,000 Pg C). The total annual soil CO2 efflux yearly exceeds the current rate of anthropogenic CO2 emissions from deforestation and burning of fossil fuels by a factor of 10. Subtle changes in soil organic carbon (SOC) processing (formation and decomposition) are, therefore, highly relevant to the global carbon cycle as soils have the potential to enhance or mitigate current increases in atmospheric CO2.