The size and age of plants have more of an impact on their productivity than temperature and precipitation, according to a landmark study by University of Arizona researchers. UA professor Brian Enquist and postdoctoral researcher Sean Michaletz, along with collaborators Dongliang Cheng from Fujian Normal University in China and Drew Kerkhoff from Kenyon College in Gambier, Ohio, have combined a new mathematical theory with data from more than 1,000 forests across the world to show that climate has a relatively minor direct effect on net primary productivity, or the amount of biomass – wood or any other plant materials – that plants produce by harvesting sunlight, water and carbon dioxide.

More extreme droughts, floods and wildfires – these are just some of the impacts of climate change that won't just occur in the distant future to our great-great grandchildren, but are happening now. To address the changing climate's current effects on communities in the U.S., President Barack Obama announced a plan to strengthen national infrastructure and help cities, states and tribal communities better prepare for and recover from natural disasters.

You have probably heard that melting permafrost is a big contributor to increasing the levels of greenhouse gases in our atmosphere, and that melting permafrost may even cause an unstoppable acceleration of global warming. New research, however, supported by the National Science Foundation (NSF), counters this widely-held scientific view that thawing permafrost uniformly accelerates atmospheric warming, indicating instead that certain arctic lakes store more greenhouse gases than they emit into the atmosphere. The study, published this week in the journal Nature, focuses on thermokarst lakes, which occur as permafrost thaws and creates surface depressions that fill with melted fresh water, converting what was previously frozen land into lakes.

This week, on July 15, NASA's Aura satellite celebrated its 10th anniversary. Happy belated, Aura! The mission of Aura, which is Latin for breeze, centers on obtaining measurements of ozone, aerosols and key gases throughout the atmosphere. And after one decade in space, the satellite has provided vital data about the cause, concentrations and impact of major air pollutants.

When it rains, where does the water go? Well for one, a lot of rainwater will funnel its way off roads and impermeable surfaces and will make its way into storm sewers. Another path might be directly into rivers and lakes. Or, rainwater might get soaked up by soil where it will then infiltrate into the ground and replenish aquifers. But just how deep does this rainwater infiltrate? According to new research, rainwater can penetrate below the Earth's fractured upper crust - which is at least eight miles below the Earth's surface!

US Government scientists have developed a new high-resolution climate model that shows southwestern Australia's long-term decline in fall and winter rainfall is caused by increases in manmade greenhouse gas emissions and ozone depletion. "This new high-resolution climate model is able to simulate regional-scale precipitation with considerably improved accuracy compared to previous generation models," said Tom Delworth, a research scientist at NOAA's Geophysical Fluid Dynamics Laboratory in Princeton, N.J., who helped develop the new model and is co-author of the research.

London's urban heat island effect, which keeps night-time temperatures in the capital warmer than in surrounding rural areas, may have been underestimated by up to 45 per cent. The heat can pose serious health risks, particularly for the elderly and very young.

In a study that may both reflect and foretell a warming planet's impact on human health, a research team found a link between hot days and kidney stones in 60,000 patients in several US cities with varying climates. "We found that as daily temperatures rise, there is a rapid increase in the probability of patients presenting over the next 20 days with kidney stones," said study leader Gregory E. Tasian, MD, MSc, MSCE, a pediatric urologist and epidemiologist at The Children's Hospital of Philadelphia (CHOP), who is on the staff of the Hospital's Kidney Stone Center as well as the Hospital's Center for Pediatric Clinical Effectiveness (CPCE).

Log books from British whaling ships more than 200 years ago have given new insights into the history of the Arctic sea ice, reports Tim Radford. A new study reveals that the scale of ice melt in the Arctic over the last few decades is new and unprecedented. The retreat of the ice in the last 30 years is part of a more recent and new pattern of climate change. British whaling ships from Tyneside in the north-east of England made 458 trips to the edge of the Arctic ice between 1750 and 1850.

Astrobiologists from the United States and Germany recorded the highest known level of solar UV radiation to reach Earth's surface. This was around 10 years ago. On December 29, 2003, the UV Index (UVI) peaked, reaching the blistering number of 43.3 over the Andes Mountains in Bolivia. To put this in context, a beachgoer in the United States would expect a UVI of 8 or 9 on a summer day. Even with an 8 or a 9, one may not escape the day without sunburn. Nonetheless, it has taken scientists 10 years to detail a report of this data while taking into account all of the variables and anomalies monitored from an international network of dosimeters – or Eldonets (European Light Dosimeter Network) – that measure UV radiation worldwide. This system is comprised of more than 100 stations across 5 continents to account for variation in the atmosphere above each station.