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.
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.
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.
In their recent Science article, Marcott and colleagues present a reconstruction of Earth’s mean surface temperature over the last 11,300 years – the Holocene. Why is this important? It is the most comprehensive and inclusive reconstruction to date from which to assess how novel our current temperatures are compared with those in the recent geologic past. In other words, are we experiencing average temperatures that are essentially unprecedented over this timeframe?
The Antarctic Peninsula is one the regions of the world that has experienced the highest impacts of climate change. In the last 40 years the mean annual air temperature has increased 2.8 degrees C causing massive ice shelves to disintegrate, declines in sea ice extent and a strong impact on all trophic levels of the ecosystem. Dr.
Respiration by plants and microorganisms is primarily responsible for mediating carbon exchanges between the biosphere and atmosphere. Climate warming has the potential to influence the activity of these organisms, altering the exchanges between carbon pools. Traditionally, the respiratory release of CO2 into the atmosphere is thought to be more temperature-sensitive than photosynthesis (carbon fixation), generating a positive climate-ecosystem carbon feedback with the potential to accelerate climate warming by up to 1.4 times.
Biodiversity is an extremely important component of the Earth System that is both difficult to quantify and vital to understand. In a recent special issue of Remote Sensing, several articles describe the progress we have made in quantifying various aspects of biodiversity using novel imaging technologies. Not long ago the prospect of identifying species from space was considered extremely unlikely, but in the editorial titled “Biological Diversity Mapping Comes of Age,” Dr.
Earth’s climate system includes several patterns of climate variability at the hemispheric scale. One of the best known of these is the El-Nino/Southern Oscillation, which influences weather across much of the globe. Another important feature of the climate system is the Southern Annular Mode (also known as the Antarctic Ocean Oscillation), which is an index of the pressure gradient between the mid- and high-latitudes in the Southern Hemisphere. Over the last few decades, the dominance of the positive phase of the Southern Annular Mode has been increasing.
Methane, a greenhouse gas second in importance only to carbon dioxide, has built up rapidly in the atmosphere since the Industrial Revolution due to human emissions. It was believed that prior to the 19th century,