Will changes in climate wipe out mammals in Arctic and sub-Arctic areas?

AlphaGalileo: The climate changes depicted by climatologists up to the year 2080 will benefit most mammals that live in northern Europe’s Arctic and sub-Arctic land areas today if they are able to reach their new climatic ranges. This is the conclusion drawn by ecologists at Umeå University in a recently published article in the journal Plos ONE.

The scientists Anouschka Hof, Roland Jansson, and Christer Nilsson of the Department of Ecology and Environmental Science at Umeå University investigated how future climate changes may come to impact mammals in northern Europe’s Arctic and sub-Arctic land areas, excluding the Arctic seas and islands. These land masses are assumed to undergo major changes in climate, and their natural ecology is also regarded as especially susceptible to changes.

By modeling the distribution of species, the researchers have determined that the predicted climate changes up to the year 2080 will benefit most mammals that live in these areas today, with the exception of some specialists in cold climate, such as the Arctic fox and the lemming.

“This will be the case only on the condition that the species can reach the areas that take on the climate these animals are adapted to. We maintain that it is highly improbable that all mammals will be able to do so, owing partly to the increased fragmentation of their living environments caused by human beings. Such species will reduce the extent of their distribution instead,” says Christer Nilsson, professor of landscape ecology.

The researchers also show that even if climate changes as such do not threaten the majority of Arctic and sub-Arctic mammals, changes in the species mix may do so, for instance because predators and their potential prey that previously did not live together may wind up in the same areas....

A reindeer shot near Svalbard by Per Harald Olsen (Perhols), Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license.

Emerging consensus shows climate change already having major effects on ecosystems and species

US Geological Survey: Plant and animal species are shifting their geographic ranges and the timing of their life events – such as flowering, laying eggs or migrating – at faster rates than researchers documented just a few years ago, according to a technical report on biodiversity and ecosystems used as scientific input for the 2013 Third National Climate Assessment.

The report, Impacts of Climate Change on Biodiversity, Ecosystems, and Ecosystem Services, synthesizes the scientific understanding of the way climate change is affecting ecosystems, ecosystem services and the diversity of species, as well as what strategies might be used by natural resource practitioners to decrease current and future risks. More than 60 federal, academic and other scientists, including the lead authors from the U.S. Geological Survey, the National Wildlife Federation and Arizona State University in Tempe, authored the assessment.

"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," said Nancy Grimm, a scientist at ASU and a lead author of the report.

...Another key finding is the mounting evidence that population declines and increased extinction risks for some plant and animal species can be directly attributed to climate change. The most vulnerable species are those already degraded by other human-caused stressors such as pollution or exploitation, unable to shift their geographic range or timing of key life events, or that have narrow environmental or ecological tolerance. For example, species that must live at high altitudes or live in cold water with a narrow temperature range, such as salmon, face an even greater risk due to climate change.

"The report clearly indicates that as climate change continues to impact ecological systems, a net loss of global species’ diversity, as well as major shifts in the provision of ecosystem services, are quite likely," said Michelle Staudinger, a lead author of the report and a USGS and University of Missouri scientist....

Snow geese at Sacramento National Wildlife Refuge, shot by Brocken Inaglory, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported licence

Drought in the Horn of Africa delays migrating birds

University of Copenhagen News: The catastrophic drought last year in the Horn of Africa affected millions of people but also caused the extremely late arrival into northern Europe of several migratory songbird species, a study published today in Science shows. Details of the migration route was revealed by data collected from small backpacks fitted on birds showing that the delay resulted from an extended stay in the Horn of Africa.

The extensive 2011 drought in the Horn of Africa had significant consequences for European songbirds such as thrush nightingale and red-backed shrike. These birds visit northern Europe every spring to mate and take advantage of ample summer food resources.

However, their spring migrating route from southern Africa to northern latitudes passes directly through the Horn of Africa, where the birds stop to feed and refuel for the next stage of their migration.

"Our research was able to couple the birds’ delayed arrival in Europe with that stopover in the Horn of Africa. Here they stayed about a week longer in 2011 than in the years before and after 2011. Because of the drought, the birds would have needed longer to feed and gain energy for their onward travel, causing delayed arrival and breeding in Europe. This supports our theory that migrating animals in general are dependent on a series of areas to reach their destination," says Associate Professor Anders Tøttrup from the Center for Macroecology, Evolution and Climate at the University of Copenhagen....

Nestlings of red-backed shrike, an 1887 painting by Bruno Liljefors

Migration not always a way to adapt

IRIN: As the impact of climate change unfolds, many have predicted forbidding scenarios of millions of impoverished people flooding into often affluent countries. Yet a ground-breaking study released on 28 November reveals a more nuanced relationship between climate variability and migration, which could provide insight into how events might transpire in the coming years.

The study, carried out by Care International and the UN University (UNU) in eight countries in Asia, Africa and Latin America, reveals that in nearly all instances where rains have become too scarce for farming, people have migrated - but within the national borders.

The project also considered possible future scenarios in Tanzania, where even scarcer rains over the next 25 years were projected to double migration from vulnerable households.  The project’s researchers hope their findings will inform the UN Framework Convention on Climate Change (UNFCCC) talks, currently taking place in Doha, by persuading participants to speed up efforts to cut greenhouse gas emissions and develop effective policies to adapt to rising temperatures.

The three-year research project, Where the rain falls: climate change, hunger and human mobility, covered over 1,300 households and 2,000 individuals in Bangladesh, India, Ghana, Guatemala, Peru, Tanzania, Thailand and Vietnam. 

...It is one of the first empirical efforts to explore how poor households use migration as a risk management strategy to deal with climate stressors and food insecurity. The study also offers insight into how households adjust their behaviour in the face of these changes, which could inform how policymakers support rural communities....

Young people in Guatemala in 1980, shot by Infrogmation, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Climate-related migration often short distance and cyclical, not international

Worldwatch Institute: ... Research suggests that when climate-related migration does occur, much of it is short distance and within national borders, as opposed to international, according to new analysis conducted by Lori Hunter, Associate Professor of Sociology at the University of Colorado at Boulder, for the Worldwatch Institute’s Vital Signs Online service (www.worldwatch.org).

Recent research has added nuance to the scientific understanding of the potential connections between climate change and human migration. Previous studies over the past two decades relied largely on descriptive data and simplistic assumptions to put forward at-times alarmist estimates of future numbers of “environmental refugees,” ranging from 150 million to 1 billion people. But such broad-sweeping generalizations mask several central issues that are important in the development of appropriate policy responses. These include:

• Environmental drivers, such as changing climatic patterns, are rarely the only factor leading to migration.Rainfall shortages and heat waves interact, for example, with persistent impoverishment and land degradation, as well as political and economic pressures. In addition, in many regions women’s inability to limit their family size, combined with the unmet demand for family planning, results in unsustainable population pressures on local and natural resources.
• Environmentally related migration is not new: migration has represented a livelihood strategy for millennia.In low-lying Bangladesh, for example, migration has long served as an adaptive strategy. Over two-thirds of Bangladeshis work in agriculture, forests, or fisheries—all livelihoods that depend on environmental conditions. Natural disasters plague rural Bangladesh with regular exposure to flooding as well as crop failure due to rainfall deficits, and food insecurity abounds.
• Migration comes with costs—social, financial, and otherwise.People tend to be attached to their homelands, their cultures, and their ways of life, so it is likely that they will seek to remain close to home, and to maintain their accustomed patterns, to the extent possible.