According to climate models, by the end of this century, the western United States is still projected to warm by about another 3.5 degrees Celsius,” he told me. “And when we remember that the relationship between temperature and fire is exponential … we’re really talking about a very different western United States in 50 years.
This wasn’t supposed to be a bad year for Western wildfires.Last winter, a weak La Niña bloomed across the Pacific. It sent flume after flume of rain to North America and irrigated half the continent. Water penetrated deep into the soil of Western forests, and mammoth snowdrifts stacked up across the Sierra Nevadas. California’s drought ended in the washout.
In other words, the weeks of heat that baked the West in July and August were enough to wipe away some of the fire-dampening effect of the winter storms…
…“According to climate models, by the end of this century, the western United States is still projected to warm by about another 3.5 degrees Celsius,” he told me. “And when we remember that the relationship between temperature and fire is exponential … we’re really talking about a very different western United States in 50 years.”…
Land use change and drought favor the same species and threaten the same species so we may be losing biodiversity faster than we previously thought when we were studying these separately
Key strategies include protecting areas of wetter forests that expected to stay wet in the future; targetting conservation on wet-forest species that are particularly sensitive to habitat conversion and climate change; and incentivizing landowners in wet regions to create or maintain patches of forests near or within their farms to better balance food production and biodiversity.
Climate change and habitat conversion to agriculture are working together to homogenize nature, indicates a study in the journal Global Change Biology led by the University of California, Davis.
In other words, the more things change, the more they are the same.
While the individual impacts of climate change and habitat conversion on wildlife are well-recognized, little is known about how species respond to both stressors at once.
In northwest Costa Rica, the study’s authors surveyed birds and plants at 120 sites that included rainforests, dry forests and farmland to determine how habitat conversion and climate-change-induced droughts affect tropical wildlife. They found that different bird species thrive in drier versus wetter areas of forests. In farmlands however, birds associated with dry sites were found everywhere, even in the wettest sites.
“Across Central and South America, we are seeing large areas being converted from native forest to agriculture, and droughts are becoming more frequent,” said lead author Daniel Karp, an assistant professor in the UC Davis Department of Wildlife, Fish and Conservation Biology. “Both of these global pressures are favoring the same species and threatening the same species This means we may be losing biodiversity faster than we previously thought when we were studying climate change and habitat conversion individually.”
…most vulnerable birds at the study sites were those in the wet forests, which include tropical birds like tanagers, manakins, and woodcreepers. He noted that birds in the agricultural sites — such as blackbirds, doves, and sparrows — were more similar to those found in the dry forest, where there is less of a tree canopy and more grass cover….
Daniel S. Karp, Luke O. Frishkoff, Alejandra Echeverri, Jim Zook, Pedro Juárez, Kai M. A. Chan. Agriculture erases climate-driven β-diversity in Neotropical bird communities. Global Change Biology, 2017; DOI: 10.1111/gcb.13821
‘California Climate Science and Solutions Institute’ would fund basic- and applied-research projects designed to help the state to grapple with the hard realities of global warming with revenue from the state’s cap and trade program
California has a history of going it alone to protect the environment. Now… scientists in the Golden State are sketching plans for a home-grown climate-research institute — to the tune of hundreds of millions of dollars per year.
The initiative, which is backed by California’s flagship universities, is in the early stages of development. If it succeeds, it will represent one of the largest US investments in climate research in years. The nascent ‘California Climate Science and Solutions Institute’ would fund basic- and applied-research projects designed to help the state to grapple with the hard realities of global warming.
The project could be funded by revenue from the state’s cap-and-trade programme to reduce greenhouse-gas emissions, but its political prospects are unclear. Advocates say they have received a warm reception from California Governor Jerry Brown, but a spokesperson for Brown would say only that “discussions are ongoing”. The proposal must also clear the state legislature….
But the California initiative still faces significant challenges. Severin Borenstein, an economist at the University of California, Berkeley, warns that academics will face plenty of competition for a limited pool of cap-and-trade revenue…..Nonetheless, Borenstein favours the climate initiative, because he sees global warming as an issue on which California can have a truly global impact.
“The main way California can contribute to dealing with climate change is through innovation,” he says. “We can invent and test the technologies and processes that will allow the rest of the world to reduce their greenhouse-gas emissions.”
Drier soils and reduced water flow in rural areas — but more intense rainfall that overwhelms infrastructure and causes flooding and stormwater overflow in urban centers. That’s the finding of an exhaustive study of the world’s river systems, based on data collected from more than 43,000 rainfall stations and 5,300 river monitoring sites across 160 countries…
…”The [study] relied on observed flow and rainfall data from across the world, instead of uncertain model simulations, means we are seeing a real-world effect — one that was not at all apparent before.”
“It’s a double whammy,” said Conrad Wasko, lead author of the paper and postdoctoral fellow at UNSW’s Water Research Centre. “People are increasingly migrating to cities, where flooding is getting worse. At the same time, we need adequate flows in rural areas to sustain the agriculture to supply these burgeoning urban populations.”
…[the study] found warmer temperatures lead to more intense storms, which makes sense: a warming atmosphere means warmer air, and warmer air can store more moisture…But…why is flooding not increasing at the same rate as the higher rainfall?
The answer turned out to be the other facet of rising temperatures: more evaporation from moist soils is causing them to become drier before any new rain occurs — moist soils that are needed in rural areas to sustain vegetation and livestock. Meanwhile, small catchments and urban areas, where there are limited expanses of soil to capture and retain moisture, the same intense downpours become equally intense floods, overwhelming stormwater infrastructure and disrupting life.
Global flood damage cost more than US$50 billion in 2013; this is expected to more than double in the next 20 years as extreme storms and rainfall intensify and growing numbers of people move into urban centres. Meanwhile, global population over the next 20 years is forecast to rise another 23% from today’s 7.3 billion to 9 billion — requiring added productivity and hence greater water security….
“We need to adapt to this emerging reality,” said Sharma. “We may need to do what was done to make previously uninhabitable places liveable: engineer catchments to ensure stable and controlled access to water. Places such as California, or much of the Netherlands, thrive due to extensive civil engineering. Perhaps a similar effort is needed to deal with the consequences of a changing climate as we enter an era where water availability is not as reliable as before.”…
Conrad Wasko, Ashish Sharma. Global assessment of flood and storm extremes with increased temperatures. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-08481-1
As drought and water shortages become California’s new normal, more and more of the water that washes down drains and flushes down toilets is being cleaned and recycled for outdoor irrigation. But some public officials, taking cues from countries where water scarcity is a fact of life, want to take it further and make treated wastewater available for much more — even drinking. “This is a potential new source of water for California,” said former Assemblyman Rich Gordon. “We need to find water where we can.”
….Water recycling is more the norm in countries like Singapore, Israel, Saudi Arabia and Australia, which have long had water shortages. Israel reclaims about 80 percent of its wastewater, while Singapore reclaims almost 100 percent. The reclaimed water is extensively used to irrigate agricultural lands and recharge aquifers in Israel, while most of Singapore’s water is used for industrial purposes.
….To address the public perception issue, former Assemblyman Gordon was able to pass Assembly Bill 2022 last year. It enables water agencies in the state to distribute bottles of advanced purified recycled water for educational purposes….
A new approach for identifying the impacts of climate change and extreme weather on the variability of global and regional wheat production has been proposed by researchers. The study analyzed the effect of heat and water anomalies on crop losses over a 30-year period… [the study] finds that heat stress concurrent with drought or water excess can explain about 40% of the changes in wheat yields from one year to another.
….One finding is that in contrast to the common perception, water excess affects wheat production more than drought in several countries. Excessive precipitation and greater cloud cover, especially during sensitive development stages of the crop, are major contributors to reduced yields, as they help pests and disease proliferate and make it harder for the plants to get the oxygen and light they need….
M Zampieri, A Ceglar, F Dentener, A Toreti. Wheat yield loss attributable to heat waves, drought and water excess at the global, national and subnational scales. Environmental Research Letters, 2017; 12 (6): 064008 DOI: 10.1088/1748-9326/aa723b
The expansion of grasslands isn’t solely due to drought, but more complex climate factors are at work, both for modern Africans now and ancient Africans in the Pleistocene, suggests new research….
Researchers from the University of Utah have found a better way. By analyzing isotopes of oxygen preserved in herbivore teeth and tusks, they can quantify the aridity of the region and compare it to indicators of plant type and herbivore diet. The results show that, unexpectedly, no long-term drying trend was associated with the expansion of grasses and grazing herbivores. Instead, variability in climate events, such as rainfall timing, and interactions between plants and animals may have had more influence on our ancestors’ environment. This shows that the expansion of grasslands isn’t solely due to drought, but more complex climate factors are at work, both for modern Africans now and ancient Africans in the Pleistocene.
Scott A. Blumenthal, Naomi E. Levin, Francis H. Brown, Jean-Philip Brugal, Kendra L. Chritz, John M. Harris, Glynis E. Jehle, Thure E. Cerling. Aridity and hominin environments. Proceedings of the National Academy of Sciences, 2017; 201700597 DOI: 10.1073/pnas.1700597114
….Common sense dictates that we build water reserves during rainy years that will carry us through the lean years. While dams have been the reserve strategy in the past, recent experience has shown they have limitations…..UC Merced scientist Mohammad Safeeq has pointed to groundwater storage as a viable option, noting that California has enough unused groundwater storage capacity to hold 850 to 1,300 million-acre feet of water. This dwarfs the state’s current surface water storage capacity of 42 million-acre feet….
…Fortunately, …are currently researching and mapping areas with good recharge potential – areas with soil types that allow water to penetrate accompanied by a geologic makeup under the soil that filters and sends water to the aquifer.
Once special recharge sites are identified, we need to preserve or restore them. Here, progress is being made in both urban and in rural areas. For example, Santa Cruz and Butte Counties both have general plan language protecting important recharge sites from development.
…To get where we need to go, multi-benefit groundwater recharge projects must expand in number and scale. …working together, they can assure the ultimate success of California’s new Sustainable Groundwater Management Act….
The Earth’s rising temperature is expected to knock the global water cycle out of whack, but exactly how it will change is uncertain. Scientists, though, can look for clues as to what the future might bring in the major climate swings that have happened in the past.
A new study that does just that suggests that Earth’s rain belts could be pushed northward as the Northern Hemisphere heats up faster than the Southern Hemisphere. That shift would happen in concert with the longstanding expectation for already wet areas to see more rain and for dry ones to become more arid.
….These changes in rain distribution could have implications for future water resources, particularly in areas where water supplies are already stressed, such as the western U.S.and parts of Africa…
Biologists have shown what could be a startling drop in the amount of carbon stored in the Sierra Nevada mountains due to projected climate change and wildfire events.
….roughly half of all human-emitted carbon is absorbed by vegetation and the ocean, and is stored through natural processes — something that helps limit our actual carbon impact on the atmosphere. The problem is, as forests begin to change, due to global warming and large scale fires, the amount of forest carbon uptake will decrease, accelerating the amount of human-made carbon making its way into the atmosphere.
“Our simulations in the Sierra Nevada show that the mean amount of carbon loss from the forests under these projections could be as large as 663 teragrams,” said Hurteau. “That’s equal to about 73 percent of the total above ground carbon stock estimated in California vegetation in 2010.”
…The two factors that influence these findings are changes in climate and the likelihood of large scale forest fires. Because California is experiencing warmer and drier conditions due to global warming, certain tree species are not able to flourish across particular geographic regions like they once were. Less tree growth, means less carbon uptake in forests.
The study also shows that wildfires will play a big role in the reduction of stored carbon. And while many of these incidents will occur naturally, Hurteau says we are, in part, to blame for their significance….
…”We’ve been putting out fires for a hundred years, causing tree density to go way up. In the absence of fire that system has a lot more carbon stored in it,” explained Hurteau. “But, when you have these large fire events the amount of carbon stored in the system drops because it kills many of the trees. Whereas, in a forest that’s been maintained by regular forest fires, which is the natural ecological state, your total carbon at any given point in time can be lower but it stays more consistent.”
…Hurteau says researchers have identified strategies for reducing some of the fire risk by actively thinning forests to manage tree density and restoring surface fires. It’s an idea that seems counterproductive until you consider how volatile these ecosystems are due to the risk of large scale fires that end up destroying hundreds of thousands of acres.
…He says it’s not only for the benefit of nature but for all of us, since healthy ecosystems lead to cleaner, better regulated water flow to communities across the western United States.
Shuang Liang, Matthew D. Hurteau, Anthony LeRoy Westerling. Potential decline in carbon carrying capacity under projected climate-wildfire interactions in the Sierra Nevada. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-02686-0