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
BY MARSHALL ABRAMCZYK, MARTHA CAMPBELL, AMAN CHITKARA, MIA DIAWARA, AILEEN LERCH, AND JAMES NEWCOMB
From the intro:
Today, many experts doubt that energy systems can decarbonize fast enough to prevent this scenario. But this belief is both dangerous and wrong—dangerous because despair undercuts the will to act; and wrong because this view does not take into account events already taking place that indicate a possible pathway to a rapid energy transition.
This paper describes scenarios for transitions in energy, agriculture, and land use that together are sufficient to limit global average temperature increase to 1.5–2 C°. Unlike conventional modeling approaches, these scenarios entail patterns of disruption, innovation, and nonlinear change, harnessed at global scale, that mirror the episodic and disruptive ways that individual industries and the economy as a whole have changed historically. The great transitions in the economy, such as the Industrial Revolution, have been driven by such self-reinforcing patterns of change. Their signs are all around us….
Study finds human-driven changes in climate and land-use in Amazon’s 3rd “1-in-100 year” drought since 2005
man-made warming is accelerating the movement of water through the ecosystem, which can cause drought even if precipitation does not decrease. Warming also causes changes in the large-scale patterns of air motion (atmospheric circulation) that reduces rainfall in this region
…the Amazon region does encounter periodic droughts. There was one in 2005, another in 2010, both of which were 100-year events, and the most recent one in 2015-2016.
[The authors] quantified the precipitation deficits and water storage on the ground. They also used two different vegetation measures of drought. The results showed that the most recent drought was unprecedented in severity. ……
…the authors found that the relationship between water temperatures and drought worked well for prior droughts (the 2005 and 2010 droughts as well as 1983 and 1998 droughts, also El Niño years) but fell apart in 2015-2016.
…the predicted 2015-2016 drought should not have been nearly as severe or as large as it was. The paper also reports that the 2015-2016 drought clearly exceeded that of the 100-year events in 2005 and 2010. So, in approximately one decade, this zone has had three 100-year events. Quite astonishing…
why was SST unable to explain the 2015-2016 drought, like it had for past events? Part of it has to do with land-use changes. That is, human changes to the land surface such as deforestation. Another part is related to warming from greenhouse gases…land-use changes can affect drought. As farmers deforest, for instance, they convert woodlands and forests into agricultural land. This changes not only the darkness (reflectivity) of the land, but it also impacts the transfer of water to and from the atmosphere (evapotranspiration).
how [does] warming affects droughts… As air temperatures increase, air is able to evaporate water more rapidly and dry out surfaces. At the same time, air can contain more water vapor so that when rain does occur, it is more often in heavy downpours. These two changes underlie what is referred to as an accelerated hydrological cycle. Simply put, man-made warming is accelerating the movement of water through the ecosystem, which can cause drought even if precipitation does not decrease. Warming also causes changes in the large-scale patterns of air motion (atmospheric circulation) that reduces rainfall in this region.
Dr. Wang, who told me:
Since oceanic forcing could not fully explain the severity of the latest drought, one will have to account for the roles of greenhouse gas warming, land use land cover changes, and/or dynamic ecosystem feedback in order to advance the understanding, attribution and prediction of extreme droughts in this region. The frequent recurrence of severe droughts in the recent decade may be a precursor of what the future might have in store for this regional climate and ecosystem.
…droughts in this part of the world create an increased risk for desertification and fire occurrence and hurt the region’s ecosystem, harm trees, and accelerate the release of carbon dioxide…
Drylands are of environmental concern because broad-scale changes in these systems have the potential to affect 36 percent of the world’s human population, suggests new research.
Climate change combined with overlapping high-intensity land uses are likely to create conditions detrimental to the recreation economy, wildlife habitat, water availability and other resources in hyper-arid landscapes, or drylands, in the future, according to a paper published recently in Ecosphere. Drylands are of concern because broad-scale changes in these systems have the potential to affect 36 percent of the world’s human population…..
…The research team examined the combined effects of climate change and human land use — agriculture, recreation, energy development, mining and population growth — on a range of ecosystem functions and landscape attributes. “Our approach offers a relatively simple method for scenario development that could be applied to a wide range of change agents, ecosystem services and regions,” said lead author Stella Copeland, NAU Merriam-Powell Center post-doctoral scholar. “Tools such as these can be used to inform natural resource planning and management efforts in the United States and elsewhere.”
…The study examined four scenarios to estimate how climate change and overlapping land uses may influence ecosystem functions and landscape attributes. Although outcomes varied by scenario and characteristic, the recreation economy had the highest impacts for all scenarios; followed by vegetation and wildlife habitat and cultural and spiritual values; water availability; soil productivity; and cropland productivity….
Stella M. Copeland, John B. Bradford, Michael C. Duniway, Rudy M. Schuster. Potential impacts of overlapping land-use and climate in a sensitive dryland: a case study of the Colorado Plateau, USA. Ecosphere, 2017; 8 (5): e01823 DOI: 10.1002/ecs2.1823
Abstract: The combination of co-occurring climate change and increasing land-use is likely to affect future environmental and socioeconomic conditions in drylands; these hyper-arid to sub-humid landscapes are limited by water resources and prone to land degradation. We characterized the potential for geographic overlap among land-use practices and between land-use and climate change on the Colorado Plateau—a dryland region experiencing rapid changes in land-use and facing aridification. We characterized spatial patterns and temporal trends in aridification, land-use, and recreation at the county and 10-km2 grid scales. Increasing trends and overlapping areas of high intensity for use, including oil and gas development and recreation, and climate drying, suggest areas with high potential to experience detrimental effects to the recreation economy, water availability, vegetation and wildlife habitat, and spiritual and cultural resources. Patterns of overlap in high-intensity land-use and climate drying differ from the past, indicating the potential for novel impacts and suggesting that land managers and planners may require new strategies to adapt to changing conditions. This analytical framework for assessing the potential impacts of overlapping land-use and climate change could be applied with other drivers of change or to other regions to create scenarios at various spatial scales in support of natural resource planning efforts.
Eating healthier food could reduce greenhouse gas emissions, suggests a new study. As it turns out, some relatively small diet tweaks could add up to significant inroads in addressing climate change….To create healthier model diets, the researchers altered the standard 2,000-calorie-a-day U.S. diet, changing the sources of about half of those calories. The different model diets progressively reduced the amount of red and processed meats, with the most stringent diet eliminating them completely. Fruit and vegetable intake was doubled, and peas and beans increased to replace the meat protein removed. Refined grains were partially replaced with whole grains. Added sugar, which Cleveland noted is a known health risk, was not reduced. Neither was dairy, eggs, fish or non-red meat.
“This means our estimates are probably very conservative, both in terms of health and climate change implications,” Cleveland said. “Just changing half of the diet and including only some of the diseases associated with diets, we found a huge effect. “Food has a tremendous impact on the environment,” he added. “That means that there is enormous potential for our food choices to have positive effects on our environment as well on our health and our health care costs.”…. The food system contributes about 30 percent of total U.S. greenhouse gas emissions, with the largest proportion coming from animal-based food. In addition, the poor quality of the standard U.S. diet — including high levels of red and processed meat and low levels of fruits and vegetables — is a major factor in a number of preventable diseases. The U.S. spends $3 trillion on health care every year — 18 percent of the gross domestic product — much of it allocated to diseases associated with poor diets…
Elinor Hallström, Quentin Gee, Peter Scarborough, David A. Cleveland. A healthier US diet could reduce greenhouse gas emissions from both the food and health care systems. Climatic Change, 2017; DOI: 10.1007/s10584-017-1912-5
…researchers from three continents found habitat destruction still far outstrips habitat protection across many parts of the planet….. the published study revealed more than half the planet could now be classified as completely converted to human-dominated land use.
“An area of 4.5 million square kilometres, or about two thirds the size of Australia, has been converted to human-dominated land use in the past two decades alone,” he said.
“As a consequence of past and recent habitat loss, almost half of the world’s ecoregions now must be classified at very high risk, as 25 times more land has been converted than protected.
…The researchers identified 41 ecoregions across 45 nations that are in a ‘crisis state’, where humans have converted more than 10 per cent of the little remaining habitat in the past two decades. “These crisis and at-risk ecoregions are clearly the places where targeted conservation interventions need to be prioritised,” Associate Professor Watson said. “But this means a rethink in how nations do conservation planning. Nations tend to place protected areas in remote locations, where nobody else is vying to convert the land. This does not help save threatened biodiversity, and we must urgently start strategically placing new protected areas in zones that will be destroyed without conservation action.”…
James E.M. Watson, Kendall R. Jones, Richard A. Fuller, Moreno Di Marco, Daniel B. Segan, Stuart H.M. Butchart, James R. Allan, Eve McDonald-Madden, Oscar Venter. Persistent Disparities between Recent Rates of Habitat Conversion and Protection and Implications for Future Global Conservation Targets. Conservation Letters, 2016; DOI: 10.1111/conl.12295
Kenya announced on September 8th that it will restore 5.1 million hectares (12.6 million acres) of degraded land, an area roughly the size of Denmark, to more productive use. The move is poised to improve livelihoods, curb climate change, safeguard biodiversity and more.
As a result of poor land use, including overcultivation and overgrazing, Kenya has been quickly losing land to desertification. The drylands that make up much of the country are particularly susceptible. Kenya’s restoration plan is not only notable because it will reverse some of this degradation, but because of how the country set its international target….…. The benefits of these actions go way beyond land—restoration can bolster several sectors of the environment and economy all at once. Estimates show carbon sequestered by restored trees will lower the country’s CO2 emissions by 3.7 percent (14.5 percent of Kenya’s greenhouse gas emissions came from forestry and land-use change in 2011). These reductions will in turn contribute towards other international environmental agreements, such as Kenya’s nationally determined contribution (NDC) to reduce its emissions 30 percent below business as usual by 2030….
About three-quarters of Kenyans are farmers, and many citizens rely on land and resources for their livelihoods. Continent-wide, 3 percent of agricultural productivity is lost due to soil and nutrient loss. Restoration can boost the quality of soil, reduce drought and erosion, and increase crop yields. Restoring degraded lands to productivity can also improve air and water quality for residents. In particular, land restoration will benefit Kenya’s least-advantaged, including members of nomadic tribes that make their living by grazing livestock and growing food crops in the rangelands. These arid and semi-arid landscapes constitute 80 percent of the country, and are widely degraded. Hitting the 5.1 million hectare target means wide areas of rangeland will have to be restored.
… Kenya’s commitment is just the latest addition to growing global and regional restoration movements. The Bonn Challenge reached in 2011 aims to restore 150 million hectares (371 million acres) of degraded land by 2020; 350 million (865 million acres) by 2030. So far, 38 countries, now including Kenya, have made commitments to restore degraded lands.
Regionally, Kenya joins Burundi, Central African Republic, Cote d’Ivoire, Democratic Republic of the Congo, Ghana, Ethiopia, Guinea, Liberia, Madagascar, Malawi, Mozambique, Niger, Republic of the Congo, Rwanda and Uganda in making restoration commitments. Collectively, they’ve promised to restore 46 million hectares (114 million acres) by 2030, goals that support the Bonn Challenge and AFR100, a regional, country-led initiative to restore 100 million hectares (247 million acres) of degraded land in Africa.
It’s getting hot out there. Every one of the past 14 months has broken the global temperature record. Ice cover in the Arctic sea just hit a new low, at 525,000 square miles less than normal. And apparently we’re not doing much to stop it: according to Professor Kevin Anderson, one of Britain’s leading climate scientists, we’ve already blown our chances of keeping global warming below the “safe” threshold of 1.5 degrees.
If we want to stay below the upper ceiling of 2 degrees, though, we still have a shot. But it’s going to take a monumental effort. Anderson and his colleagues estimate that in order to keep within this threshold, we need to start reducing emissions by a sobering 8%–10% per year, from now until we reach “net zero” in 2050. If that doesn’t sound difficult enough, here’s the clincher: efficiency improvements and clean energy technologies will only win us reductions of about 4% per year at most.
….How to make up the difference is one of the biggest questions of the 21st century. There are a number of proposals out there. One is to capture the CO2 that pours out of our power stations, liquefy it, and store it in chambers deep under the ground. Another is to seed the oceans with iron to trigger huge algae blooms that will absorb CO2. Others take a different approach, such as putting giant mirrors in space to deflect some of the sun’s rays, or pumping aerosols into the stratosphere to create man-made clouds. Unfortunately, in all of these cases either the risks are too dangerous, or we don’t have the technology yet. This leaves us in a bit of a bind. But while engineers are scrambling to come up with grand geo-engineering schemes, they may be overlooking a simpler, less glamorous solution. It has to do with soil.
Soil is the second biggest reservoir of carbon on the planet, next to the oceans. It holds four times more carbon than all the plants and trees in the world. But human activity like deforestation and industrial farming – with its intensive ploughing, monoculture and heavy use of chemical fertilisers and pesticides – is ruining our soils at breakneck speed, killing the organic materials that they contain. Now 40% of agricultural soil is classed as “degraded” or “seriously degraded”. In fact, industrial farming has so damaged our soils that a third of the world’s farmland has been destroyed in the past four decades.
As our soils degrade, they are losing their ability to hold carbon, releasing enormous plumes of CO2 [pdf] into the atmosphere. There is, however, a solution. Scientists and farmers around the world are pointing out that we can regenerate degraded soils by switching from intensive industrial farming to more ecological methods – not just organic fertiliser, but also no-tillage, composting, and crop rotation. Here’s the brilliant part: as the soils recover, they not only regain their capacity to hold CO2, they begin to actively pull additional CO2 out of the atmosphere.
The battle here is not just between two different methods. It is between two different ways of relating to the land
The science on this is quite exciting. A study published recently by the US National Academy of Sciences claims that regenerative farming can sequester 3% of our global carbon emissions. An article in Science suggests it could be up to 15%. And new research from the Rodale Institute in Pennsylvania, although not yet peer-reviewed, says sequestration rates could be as high as 40%. The same report argues that if we apply regenerative techniques to the world’s pastureland as well, we could capture more than 100% of global emissions. In other words, regenerative farming may be our best shot at actually cooling the planet….
Andreas Gattingera, et al Enhanced top soil carbon stocks under organic farming PNAS 2012 vol. 109 no. 44 Andreas Gattinger, 18226–18231, doi: 10.1073/pnas.1209429109
… a new map of the ecological footprint of humankind shows 97 per cent of the most species-rich places on Earth have been seriously altered….”The most species-rich parts of the planet — especially including the tropical rainforests — have been hit hardest. In total, around 97 per cent of Earth’s biologically richest real estate has been seriously altered by humans,” he said. The scientists found environmental pressures are widespread, with only a few very remote areas escaping damage.
“Humans are the most voracious consumers planet Earth has ever seen. With our land-use, hunting and other exploitative activities, we are now directly impacting three-quarters of the Earth’s land surface,” said Professor Laurance… Professor Laurance said the suitability of lands for agriculture appears to be a major determinant in where ecological pressures appeared around the globe.
“The bottom line is that we need to slow rampant population growth, especially in Africa and parts of Asia, and demand that people in wealthy nations consume less,” he said.
The updated and temporally intercomparable global terrestrial human footprint maps and the data behind have been published in Nature Communications and Nature Scientific Data.
Oscar Venter, Eric W. Sanderson, Ainhoa Magrach, James R. Allan, Jutta Beher, Kendall R. Jones, Hugh P. Possingham, William F. Laurance, Peter Wood, Balázs M. Fekete, Marc A. Levy, James E. M. Watson. Sixteen years of change in the global terrestrial human footprint and implications for biodiversity conservation. Nature Communications, 2016; 7: 12558 DOI: 10.1038/ncomms12558
Increasing woody vegetation and reducing land use intensity could mitigate the impacts of climate change on insect biodiversity, according to new research by the University of New England, the NSW Office of Environment and Heritage, and the University of Melbourne.
Associate Professor Nigel Andrew from UNE’s School of Environmental and Rural Sciences says he and colleagues set out to assess how adapting landscapes can improve insect biodiversity conservation with a changing climate.
“We found that having more native trees and shrubs on a farm will enhance ant biodiversity and help mitigate the impacts of climate change. If you have a lot of exotic vegetation and bare ground, then many ant species will become more vulnerable to rapid change” said A/Prof Andrew.
Researchers sampled ant biodiversity across a 270-kilometre elevation gradient, west of Armidale, in New South Wales. The sites they sampled varied in vegetation cover and land-use.
A/Prof Andrew says 210-thousand arthropods were collected and sorted into major groups, and ants (making up 63% of the collection) were identified further to species level.
“There was greater ant richness associated with greater native woody plant canopy cover, while there was lower species richness with higher cultivation, grazing intensity and exotic plants.”
A/Prof Andrew says ant diversity is critical for the environment and landholders. “Ants dominate the environment we live in so if you lose ant species you can lose ecosystem functions. Ants collect seeds, aerate the soil and predate on pests. If you change the type of ants in an environment you can change the dynamics and ecology of your landscape. Once lost, the remaining species may not be as efficient at delivering function to the environment so the ecosystem can become less resilient to change.”
Researchers are using predictive modelling to help land managers see the impact that changing grazing intensity or the type of land cover, can have on ant richness.
“If you are able to modify land practises, if you want to build in resilience to environmental change on your farm then managing and increasing native vegetation is an important component: not only will it help in the health of the landscape but it will also help them become more adaptable to a warming climate.”