A new report documents how climate change is already causing rapid, massive changes with "cascading effects" on ecosystems and biodiversity.
The report (pdf), led by the US Geological Survey, the National Wildlife Federation and Arizona State University, foresees a global loss of biodiversity and major shifts in ecosystems.
"These geographic range and timing changes are causing cascading effects that extend through ecosystems, bringing together species that haven't previously interacted and creating mismatches between animals and their food sources," states Nancy Grimm, a scientist at ASU and a lead author of the report.
And these changes will have direct consequences on humans, Amanda Staudt, a NWF climate scientist and a lead author on the report adds, as many ecosystems serve as a backbone in the defense of storm damage.
"Shifting climate conditions are affecting valuable ecosystem services, such as the role that coastal habitats play in dampening storm surge or the ability of our forests to provide timber and help filter our drinking water."
Among the animals in the US affected by climate change already underway, the report states, are climate-induced changes in pests and pathogens that have been deadly to some conifer forests, small mammals which are seeking higher elevations or having their already high elevation habitats shrunk and a fragmentation in habitat for wolverines.
The USGS offers some of the key findings of the report:
- Changes in precipitation and extreme weather events can overwhelm the ability of natural systems to reduce or prevent harm to people from these events. For example, more frequent heavy rainfall events increase the movement of nutrients and pollutants to downstream ecosystems, likely resulting not only in ecosystem change, but also in adverse changes in the quality of drinking water and a greater risk of waterborne-disease outbreaks.
- Changes in winter have big and surprising effects on ecosystems and their services. Changes in soil freezing, snow cover and air temperature affect the ability of ecosystems to store carbon, which, in turn, influences agricultural and forest production. Seasonally snow-covered regions are especially susceptible to climate change because small precipitation or temperature shifts can cause large ecosystem changes. Longer growing seasons and warmer winters are already increasing the likelihood of pest outbreaks, leading to tree mortality and more intense, extensive fires. Decreased or unreliable snowfall for winter sports and recreation will likely cause high future economic losses.
- The ecosystem services provided by coastal habitats are especially vulnerable to sea-level rise and more severe storms. The Atlantic and Gulf of Mexico coasts are most vulnerable to the loss of coastal protection services provided by wetlands and coral reefs. Along the Pacific coast, long-term dune erosion caused by increasing wave heights is projected to cause problems for communities and for recreational beach activities. However, other kinds of recreation will probably improve due to better weather, with the net effect being that visitors and tourism dollars will shift away from some communities in favor of others.
- Climate change adaptation strategies are vital for the conservation of diverse species and effective natural resource policy and management. As more adaptive management approaches are developed, resource managers can enhance the country’s ability to respond to the impacts of climate change through forward-looking and climate science-informed goals and actions.
- Ecological monitoring needs to be improved and better coordinated among federal and state agencies to ensure the impacts of climate change are adequately monitored and to support ecological research, management, assessment and policy. Existing tracking networks in the United States will need to improve coverage through time and in geographic area to detect and track climate-induced shifts in ecosystems and species.