Changes in population growth and composition, including aging and urbanization, could significantly affect global emissions of carbon dioxide says a new study in PNAS.

El Niño and La Niña are counterparts in the El Niño-Southern Oscillation (ENSO), a cyclic warming and cooling of the eastern and central Pacific Ocean that exerts a major influence on global weather patterns, but they are not mirror images.

A team of scientists led by NCAR’s Keith Oleson has incorporated urban areas into a global climate model. The development is important because most models used for predicting future climate change do not account for the urban “heat island” effect.

Just as the U.S. economy began a dramatic nosedive in 2007, so did the Arctic’s summertime sea ice. In the summer of 2010, the ice—much like the economy—continued to struggle.

In 1988, it was the spectre of Yellowstone National Park on fire. In 2003, it was the horror of thousands dying from heat in prosperous western Europe. The planet’s standout heat wave in 2010 plagued much of European Russia, including Moscow.