paleoclimate
Megadroughts in North America: placing IPCC projections of hydroclimatic change in a long-term palaeoclimate context
Variable oceanic influences on western North American drought over the last 1200 years
Hockey-Stick Researcher Exonerated in Penn State Investigation
The research of Michael Mann, who in 1999 published the “hockey stick” diagram illustrating the apparent effect of human activity on climate change, has consistently been a target of climate change skeptics. They have accused Mann of manipulating data, destroying records, and restricting progress in studying global warming.
Tropical Pacific Played Role in Southwest Medieval Megadroughts
Did Climate Change Drive Human Evolution
UA geoscientist Andrew Cohen has been sampling lake sediments for clues about climate history over millions of years. The sediments reveal not only information about temperature and precipitation, but include fossil evidence of life forms at the time.
CO2 Concentrations and Temperature Have Tracked Closely Over the Last 300,000 Years
As ice core records from Vostok, Antarctica show, the temperature near the South Pole has varied by more than 20º F during the past 350,000 years in a regular pattern that constitutes the ice age/interglacial cycles.
Milankovitch Cycles Drive Ice Age Cycles
Schematic of the Earth's orbital changes (Milankovitch cycles) that moderate insolation and drive the ice age cycles.
Reconstructed Naturalized Colorado River Flow at Lees Ferry Near Page, Arizona
Time series plot of past Colorado River flows created by analyzing tree-rings. The plot displays the 25-year running average of the reconstructed flows. Flows are plotted as a percentage of the 1906–2004 average of observed natural flows (18.5 billion cubic meters or 15.0 million acre-feet). The red horizontal line is the lowest 25-year running mean of observed flows (1953-1977).
Temperature and CO2 Concentration in the Atmosphere Over the Past 400,000 Years
Over the last 400,000 years the Earth's climate has been unstable, with very significant temperature changes, going from a warm climate to an ice age in as rapidly as a few decades. These rapid changes suggest that climate may be quite sensitive to internal or external climate forcings and feedbacks. This figures have been derived from the Vostok ice core, taken in Antarctica.