While natural forces have influenced Earth’s climate (and always will), human-induced changes in atmospheric greenhouse gas levels are playing an increasingly dominant role. The significant increase in average global temperatures over the past half-century can be attributed to human activities with a certainty of more than 90 percent. Temperature rises have already affected various natural systems in many regions. Continued greenhouse gas emissions at or above current rates would cause further warming and induce climate changes during the 21st century that would very likely be larger than those observed during the 20th century. Temperatures & CO2 levels are rising
WHOI geochemist Scott Doney and colleagues are leading efforts to measure the ocean’s ability to continue to absorb excess greenhouse gases and help offset global warming. » More information Iron fertilization and the ocean’s ‘twilight zone’ WHOI biogeochemist Ken Buesseler has shed light on the “twilight zone,” a dim ocean layer that acts as a critical gateway allowing some carbon-filled particles to sink to the depths. The research is key for as-sessing strategies to mitigate climate change by fertilizing the oceans with iron—to promote blooms of photosynthetic marine plants and transfer more CO2 from the air to the deep ocean. » More information Do jelly-like animals help shunt CO2 to the deep sea? WHOI biologist Larry Madin is investigating salps, small transparent ocean creatures that swarm by the billions. Salps may transport tons of carbon per day from the ocean surface to the deep sea and keep it from re-entering the atmosphere. » More information Precipitation patterns have changed
WHOI physical oceanographers Lisan Yu and Bob Weller are integrating observations from satellites, moorings, ships, and models to advance understanding of critical air-sea exchanges of heat, fresh water, and momentum that affect evaporation and rainfall patterns. » More information Sensitive but tough sensors to get precise, essential data The WHOI Upper Ocean Processes Group has developed integrated systems for moorings that can measure heat, sunlight, wind speed and direction, precipitation, barometric pressure, humidity, air temperature, sea surface temperature, and salinity—key data computer models needed to calculate climate. » More information Oceans are warming; salinity is changing
WHOI physical oceanographer Ruth Curry and colleagues are analyzing temperature and salinity data collected throughout the oceans to investigate whether climate change is affecting ocean circulation and the global water cycle, and vice versa. » More information Monitoring the global water cycle WHOI physical oceanographer Ray Schmitt and engineer Bob Petitt are designing a self-cleaning sensor to solve the hurdle of biofouling. Used on drifters, the sensor will be able to obtain extensive salinity measurements that reveal patterns of evaporation and precipitation over the ocean. » More information Rising temperatures, rising disease? WHOI biologist Rebecca Gast is exploring whether warming ocean temperatures, among other factors, may make it easier for human pathogens to survive in coastal waters. WHOI scientists Don Anderson and Dennis McGillicuddy are investigating links between climate changes and harmful algal blooms. » More information Extreme weather events are more frequent
WHOI geologist Jeff Donnelly has systematically collected evidence from around the world to piece together a long-term chronicle of tropical storms and hurricanes in preindustrial times as a means to better predict the frequency and intensity of future storms. » More information Reconstructing the history of water levels in lakes from Cape Cod to New York over the past 11,000 years, he has found long-lasting droughts that could foretell future conditions in the Northeast in an era of global warming. » More information Ice and snow cover are disappearing
WHOI geologist Sarah Das has established ice camps on Greenland to investigate a theory that warmer temperatures are creating more and larger lakes atop the ice sheet, which cause fractures in the ice that leak water to the glacial base and lubricate slippage into the sea. Once started, the phenomenon could be hard to reverse. » More information The Arctic region is vulnerable
WHOI physical oceanographer Al Plueddeman is using robotic vehicles to learn how waters entering from the Pacific are modified to help create the Arctic halocline—a layer of cold, salty water that shields sea ice from deeper, warmer water that could melt it. Changing climate potentially could cause the halocline to weaken or disappear. » More information WHOI physical oceanographer Bob Pickart is tracking waters over the Alaskan continental shelf and into the Arctic Ocean interior, using the Arctic Winch, a device that can get sensors in and out of ice-infested surface waters from below. » More information WHOI physical oceanographer Andrey Proshutinsky established a long-term observing network for the Beaufort Gyre, the “flywheel of Arctic climate,” which alternately holds and releases large amounts of cold, relatively fresh water. » More information WHOI physical oceanographers John Toole and Rick Krishfield are deploying Ice-Tethered Profilers, long-term moorings installed on drifting ice floes that measure water properties below and send data back daily. » More information Will climate change upset the Arctic’s fertile ecosystem? WHOI biologist Carin Ashjian is investigating the oceanographic and biological conditions that sustain the Arctic’s delicately balanced food web—from phytoplankton to whales and Iñupiat societies. » More information Sea levels are rising
WHOI geologist Bill Thompson is examining links between past changes in sea level and climate. Corals are excellent indicators of sea level because they must grow in sunlight near the sea surface. Developing new methods to precisely date corals, he is finding that sea level has risen more frequently and abruptly in the past than previously suspected. » More information Ocean acidity is changing
WHOI geochemist Scott Doney has led research and public outreach efforts warning that corrosive chemical conditions in the ocean could be reached within 50 to 100 years. » More information WHOI researcher Anne Cohen is investigating ocean acidification’s impacts on corals’ ability to build their skeletons. » More information Biologist Sonya Dyhrman is examining potential impacts on coccolithophores—abundant, ecologically important one-celled marine plants that surround themselves with calcite plates. » More information Abrupt climate change is a wild card
WHOI paleoceanographers Jerry McManus and Delia Oppo’s studies of seafloor sediments—and geochemist Laura Robinson’s analyses of deep-sea corals—provide clues to past ocean circulation and climate changes, and their potential in the future. » More information » More information Monitoring the ocean’s response to climate change WHOI established and maintains Line W, a long-term ocean observatory located at a strategic junction of northbound and southbound North Atlantic currents that play a major role in regulating climate. » More information How climate change can affect human and natural systemsA summary of key impacts of increasing global temperatures identified by the 2007 IPCC report:Water • Billions of people will be exposed to stresses on their water supplies. • Climate change will exacerbate water stress in some regions and alleviate it in others. • Developing nations with little capacity to manage water resources will be hardest hit. • Areas that depend on water supplies stored in glaciers and snow cover (more than 16% of world population) face scarcities as glaciers continue to melt and eventually disappear. Food • Increased temperatures, heat waves, precipitation changes, drought, and pests will harm agricultural production over much of the globe, though some regions will benefit. Coasts • Coastal populations will be exposed to more flooding, erosion, and inundation from rising sea levels and more intense storms, especially in low-lying areas and on small islands. Health • Rising temperatures and heat waves will increase the number of heat-related deaths (outweighing a decrease in deaths from cold exposure). • Higher ozone levels will increase the frequency of cardiorespiratory disease. • Climate changes will help spread vector-borne and pathogenic diseases such as malaria, dengue fever, and cholera. • Increased flooding will harm human health directly, and also indirectly—by facilitating the spread of disease and damaging health infrastructure. Ecosystems • About 20% to 30% of plant and animal species are at increased risk of extinction. • Progressive acidification of the oceans will have negative impacts on marine organisms critical to the ocean food web. • Widespread mortality of biodiverse coral reefs is expected. • Decreased rainfall in some regions will increase the risk of wildfires. Economic Costs • Damages from climate change are likely to be significant and increase over time. Global mean losses could be 1% to 5% of gross domestic product for a likely 4°C warming over the next century. Originally published: May 20, 2007 Last updated: September 3, 2009 | ||||||||||||||
Copyright ©2007 Woods Hole Oceanographic Institution, All Rights Reserved. Contact | Privacy Policy | Site Map | RSS | Support WHOI Research | Internal |
