• Helping policymakers plan for sea level rise

    A new study could help protect more than thirteen million American homes that will be threatened by rising sea levels by the end of the century. It is the first major study to assess the risk from rising seas using year 2100 population forecasts for all 319 coastal counties in the continental U.S. Previous impact assessments use current population figures to assess long-term effects of coastal flooding. The data can help policymakers develop practical adaptation strategies for protecting land threatened by frequent and repeated inundation.

  • Warmer spring temperatures reduce Colorado River flows

    Warmer-than-average spring temperatures reduce upper Colorado River flows more than previously recognized, according to a new report. The study, the first to examine the instrumental historical record, discovers that temperature has played a larger role in streamflow and in exacerbating drought since the 1980s.

  • Sea level rise threatens more people than earlier estimated

    It is estimated that 1.9 billion inhabitants, or 28 percent of the world’s total population, live closer than 100 km from the coast in areas less than 100 meters above the present sea level. By 2050 the number of people in that zone is predicted to increase to 2.4 billion. These people are the most vulnerable to the rise of the sea level as well as to the increased number of floods and intensified storms.

  • Global warming increases rainfall in world's driest areas

    Global warming will increase rainfall in some of the world’s driest areas over land, with not only the wet getting wetter but the dry getting wetter as well — a phenomenon that could lead to more flash flooding.

  • Are America's cities prepared for extreme weather events?

    Infrastructure is, by design, largely unnoticed until it breaks and service fails. It is the water supply, the gas lines, bridges and dams, phone lines and cell towers, roads and culverts, train lines and railways, and the electric grid; all of the complex systems that keep our society and economy running. Engineers typically design systems to withstand reasonable worst-case conditions based on historical records; for example, an engineer builds a bridge strong enough to withstand floods based on historical rainfall and flooding. But what happens when the worst case is no longer bad enough?

  • Senior defense officials discuss arctic, Antarctic science and research

    To address the need for collaborative research in the Polar Regions, Chief of Naval Research Rear Adm. Mat Winter met in Finland two weeks ago with counterparts from five nations in a first-ever gathering of senior defense officials to coordinate science and technology research in high latitudes. While the U.S. Navy has long experience with polar operations, changing climates present new challenges — particularly for surface ships, as new water passages open up.

  • Impact of climate change on agriculture may be underestimated

    Studies of how climate change might affect agriculture generally look only at crop yields — the amount of product harvested from a given unit of land. But climate change may also influence how much land people choose to farm and the number of crops they plant each growing season. A new study takes all of these variables into account, and suggests researchers may be underestimating the total effect of climate change on the world’s food supply.

  • Seeding iron on the Pacific’s floor may not pull carbon from air as thought

    Scientists plumbing the depths of the central equatorial Pacific Ocean have found ancient sediments suggesting that one proposed way to mitigate climate warming — fertilizing the oceans with iron to produce more carbon-eating algae — may not necessarily work as envisioned.

  • Syria’s 1998-2012 drought likely its most severe in more than 900 years

    In the years before the Syrian conflict erupted, the region’s worst drought on record set in across the Levant, destroying crops and restricting water supplies in the already water-stressed region. A new study shows that that drought, from 1998 to 2012, was not just the most severe in a century of record-keeping — it was the Levant’s most severe drought in at least 500 years and likely more than 900 years.

  • Groundwater deficit growing in important western U.S. aquifers

    By 2050, climate change will increase the groundwater deficit even more for four economically important aquifers in the Western United States, a new report says. Groundwater deficits are expected to worsen in four important aquifers, creating a precarious balance between usage and recharge. The new report is the first to integrate scientists’ knowledge about groundwater in the American West with scientific models that show how climate change will affect the region.

  • Outbreaks of extreme tornados have become more common

    Most death and destruction inflicted by tornadoes in North America occurs during outbreaks — large-scale weather events that can last one to three days and span huge regions. The largest outbreak ever recorded happened in 2011. It spawned 363 tornadoes across the United States and Canada, killing more than 350 people and causing $11 billion in damage. A new study shows that the average number of tornadoes per outbreak has grown by more than 40 percent over the last half century. The likelihood of extreme outbreaks — those with many tornadoes — is also greater.

  • Climate change impact on food production could cause 500,000 extra deaths in 2050

    Climate change could kill more than 500,000 adults in 2050 worldwide due to changes in diets and bodyweight from reduced crop productivity. The research, published yesterday in The Lancet, is the strongest evidence yet that climate change could have damaging consequences for food production and health worldwide. The study found that by 2050, reduced fruit and vegetable intake could cause twice as many deaths as under-nutrition, and that three-quarters of all climate-related deaths due to changes in food production are estimated to occur in China and India.

  • Water storage strategies in Sub-Sahara Africa

    Direct abstraction of water from rivers through ponds and pumping devices seems the most attractive water storage option in Ethiopia. However, the funding agencies that may be interested in investing in such a storage system have to consider that better access to credit, and clear abstraction policies should be ensured.

  • Calculating monetary losses from floods caused by sea level rise

    Damages from extreme events like floods are even more relevant than the mean sea level itself when it comes to the costs of climate impacts for coastal regions. However, while it is now rather well understood how sea-levels will rise in the future, only small progress has been made estimating how the implied damage for cities at the coasts will increase during the next decades. Scientists now provide a method to quantify monetary losses from coastal floods under sea-level rise. For the first time, the scientists show that the damage costs consistently increase at a higher rate than the sea-level rise itself.

  • Sea-level rise in twentieth century faster than in any previous century

    Global sea level rose faster in the twentieth century than in any of the twenty-seven previous centuries, according to a new study. Moreover, without global warming, global sea level would have risen by less than half the observed twentieth century increase and might even have fallen. Instead, global sea level rose by about 14 centimeters, or 5.5 inches, from 1900 to 2000. This is a substantial increase, especially for vulnerable, low-lying coastal areas.