Category Archives: Nature

Climate change spurs changes in vegetation

Two new studies examine the impact on climate change on plants in the Northern Hemisphere, with the first looking at a broad level indicator.

From Oak Ridge National Laboratory:

Earth system models simulate Northern Hemisphere greening. Figure shows the spatial distribution of leaf area index trends [m2/m2/30yr] in the growing season [April–October] during the period of 1982–2011 in the mean of satellite observations [top], Earth system model (ESM) simulations with natural forcings alone [lower left] and ESM simulations with combined anthropogenic and natural forcings [lower right].

Earth system models simulate Northern Hemisphere greening. Figure shows the spatial distribution of leaf area index trends [m2/m2/30yr] in the growing season [April–October] during the period of 1982–2011 in the mean of satellite observations [top], Earth system model (ESM) simulations with natural forcings alone [lower left] and ESM simulations with combined anthropogenic and natural forcings [lower right].

More from the lab:

A multinational team led by the Department of Energy’s Oak Ridge National Laboratory Climate Change Science Institute has found the first positive correlation between human activity and enhanced vegetation growth.

The research team, led by Jiafu Mao of the Ecosystem Simulation Science group in the Environmental Sciences Division, used new environmental data and strict statistical methods to discover a significant human-vegetation interaction in the northern extratropical latitudes, the section of the planet spanning 30 to 75 degrees north, roughly between the Tropic of Cancer and the North Frigid Zone above the Arctic Circle.

“This is the first clear evidence of a discernible human fingerprint on physiological vegetation changes at the continental scale,” Mao said.

With the absence of long-term observational records and suitable Earth system model (ESM) simulations, the human “touch” on northern latitude greening had not been previously identified. The team used two recently available 30-year-long leaf area index data sets, 19 ESM simulations and a formal “detection and attribution” statistical algorithm to positively attribute changes in vegetation activity in the extratropical Northern Hemisphere to anthropogenic forcings, or human-induced climate inputs such as well-mixed greenhouse gas emissions.

Leaf area index – the ratio of leaf surface area to ground area – is an indicator of vegetation growth and productivity derived from satellite imaging. The remote-sensing-based LAI datasets and ESM simulations showed a significant “greening” trend over the northern extratropical latitudes vegetated area between 1982 and 2011, indicating increased vegetative productivity.

When Mao and his colleagues accounted for internal climate variability and responses to natural forcings such as volcanic eruptions and incoming solar radiation, it was clear that the greening was inconsistent with simulations of purely natural factors and could only be explained by anthropogenic greenhouse gas forcings, particularly elevated carbon dioxide concentrations.

This anthropogenic greening effect has the potential to alter natural processes on a planetary scale. Continent-wide changes in vegetative productivity, such as those in the study, impact energy exchanges, water use and carbon budgets, accelerating or slowing the pace of climate change.

Accurate detection and attribution of changes in vegetation growth patterns are essential for strategic decision-making in ecosystem management, agricultural applications and sustainable development and conservation. This is the first time the detection and attribution algorithm has been applied to terrestrial ecosystem changes such as leaf area index trends, as it is typically used to study physical climate data such as extreme events and variations in temperature or precipitation.

Mao would like to see these long-term regional- and global-scale observational data sets used in similar studies as they become available. He says the detection and attribution algorithm could be applied to study broad-scale terrestrial ecosystem dynamics, and the framework developed for this study could be used to identify and correct potential errors in next-generation ESM simulations.

The study and its results are reported in the article “Human-induced greening of the northern extratropical land surface” [$32 to read and print — esnl]  in Nature Climate Change. Other ORNL participants and coauthors were Xiaoying Shi, Peter Thornton, Dan Ricciuto and Forrest Hoffman.

The impact of climate change on a single plant species

A female valerian plant stands sentry high in the Colorado Rocky Mountains. William Petry / UCI

A female valerian plant stands sentry high in the Colorado Rocky Mountains. William Petry / UCI

The second study looks at the impact of climate change on one plant species.

From the University of California, Irvine:

For the valerian plant, higher elevations in the Colorado Rocky Mountains are becoming much more co-ed. And the primary reason appears to be climate change.

In a study [$30 to download — esnl] appearing July 1 in Science, University of California, Irvine environmental biologists Kailen Mooney and Will Petry and colleagues report that an altering climate over the past four decades has significantly changed the growth patterns of male and female Valeriana edulis over elevation. Their work is the first to fully explain sex-specific species responses to climate change.

Read the rest, after the jump. . . Continue reading

The neighborhood giant also wears a halo

Auroras on Jupiter

Auroras on Jupiter

The largest planet in our solar system, the one known for its bright, bright spot, also has a big, bright halo.

From NASA’s HubbleSite:

Astronomers are using NASA’s Hubble Space Telescope to study auroras — stunning light shows in a planet’s atmosphere — on the poles of the largest planet in the solar system, Jupiter. This observation program is supported by measurements made by NASA’s Juno spacecraft, currently on its way to Jupiter.

Jupiter, the largest planet in the solar system, is best known for its colorful storms, the most famous being the Great Red Spot. Now astronomers have focused on another beautiful feature of the planet, using the ultraviolet capabilities of NASA’s Hubble Space Telescope.

The extraordinary vivid glows shown in the new observations are known as auroras. They are created when high-energy particles enter a planet’s atmosphere near its magnetic poles and collide with atoms of gas. As well as producing beautiful images, this program aims to determine how various components of Jupiter’s auroras respond to different conditions in the solar wind, a stream of charged particles ejected from the sun.

This observation program is perfectly timed as NASA’s Juno spacecraft is currently in the solar wind near Jupiter and will enter the orbit of the planet in early July 2016. While Hubble is observing and measuring the auroras on Jupiter, Juno is measuring the properties of the solar wind itself — a perfect collaboration between a telescope and a space probe.

“These auroras are very dramatic and among the most active I have ever seen,” said Jonathan Nichols from the University of Leicester, UK, and principal investigator of the study. “It almost seems as if Jupiter is throwing a fireworks party for the imminent arrival of Juno.”

There’s more, after the jump. . . Continue reading

Drought-spawned violence plagues India

The Indian state of Madya Pradesh, located in the north-central heart of the subcontinent, is running dry, with most of the region’s reservoirs at a tenth or less of capacity and 16 percent are bone dry.

Most villages are only allotted meager water rations one or two days a week, and use of water for irrigation has been largely banned.

Violence has become endemic.

From the Thomson Reuters Foundation:

After almost 10 years of below-average rainfall and several consecutive years of drought, the region’s rivers, lakes, reservoirs and wells are drying up.

Disputes are a common problem in many places in India that face water shortages. But Indian police report that the fighting is getting more frequent and bloody. In many parts of the country, neighbours, friends and family are turning on each other, desperate to protect what little water they have left, police records suggest.

Last month, in the tribal-dominated Alirajpur district of Madhya Pradesh, 13-year-old Surmada, her brother and her uncle used a neighbour’s hand-pump, without permission, to get water for the family’s houseguests.

According to police, the owner of the pump and his son attacked the group with arrows. One pierced Surmada’s eye, killing her.

And in the village of Kanker, in Shivpuri district, a large-scale argument broke out after two motorcyclists got into an accident, causing one to spill the 15-litre (4 gallon) container of water he was carrying.

“The two later called their family members and friends and attacked each other with spears, axes and sticks,” said investigating officer Jaisingh Yadav of Sathanwada police station. Fifteen people were injured, five of them women, he said.

And it’s not just Madhya Pradesh suffering from the ongoing drought, as Governance Now reports:

Currently, 11 states are in the grip of drought which has affected 33 million people – close to a third of the population.

There are media reports of mass migration in north Karnataka. In Telangana, cases have been cited from Mahbubnagar district. Maharashtra’s drought-hit Marathwada region has seen mass exodus to Mumbai and Surat. From Jharkhand, people are heading to Kerala.

The severely affected villages in Bundelkhand, a central region divided between the states of Uttar Pradesh and Madhya Pradesh, is mostly left with women, children and aged men, said Swaraj Abhiyan founder Yogendra Yadav, who completed his 11-day-long padyatra through Marathwada and Bundelkhand on May 30.

“In villages, if you ask for an able-bodied man, 60 to 80 percent of them have migrated to urban areas to earn their livelihood. They are migrating to Delhi, Faridabad, Gurgaon, Indore and Surat. You meet elderly, children and women, but you don’t meet able-bodied men in the village. It’s an entirely migrant-dependent economy right now,” Yadav told Governance Now.

The acute distress due to crop failure in the last three years in Bundelkhand and Marathwada has either led to mass exodus or suicides. At least 216 farmers have committed suicides in Maharashtra alone.

Relief is in sight, according to government forecasters, with a heavy monsoon season forecast in the wake of the devastating El Niño-spawned drought.

But the rains may prove partly ineffective in relieving financial stresses on debt-plagued farmers, who have suffered from low harvests. The reason: Their innate conservatism is causing them to sow less ground.

From The Gulf Today:

From Maharashtra and Madhya Pradesh to Rajasthan and Gujarat, farmers ruined by a devastating drought are still edgy about sowing, despite resounding forecasts of a surplus monsoon.

Planting of major crops is 24 per cent lower than what was sown by this time last year.

Even state governments are treading cautiously.

Maharashtra, for instance, had asked farmers to hold back sowing till June 18.

Till now, the monsoon has been 16 per cent deficient, which means it has to cover a lot of ground in July.

Reservoir levels are still barely 15 per cent of their storage capacity.

North American climate change impacts fish

“Scientific studies between 1985 and 2015 that document climate change on North American inland fish.  The color of the dots represents the fish response to climate change in each study.”

Scientific studies between 1985 and 2015 that document climate change on North American inland fish. The color of the dots represents the fish response to climate change in each study.

While most reports on the impact of climate changes on fish populations have focused on the globe’s warming and acidifying oceans, changes are also being found in North America’s freshwater streams, lakes, and rivers.

From the U.S. Geological Survey:

Climate change is already affecting inland fish across North America — including some fish that are popular with anglers. Scientists are seeing a variety of changes in how inland fish reproduce, grow and where they can live, according to four new studies published today in a special issue of Fisheries magazine.

Fish that have the most documented risk include those living in arid environments and coldwater species such as sockeye salmon, lake trout, walleye, and prey fish that larger species depend on for food. Climate change can cause suboptimal habitat for some fish; warmer water, for example, can stress coldwater fish. When stressed, fish tend to eat less and grow less. For other fish, climate change is creating more suitable habitat; smallmouth bass populations, for example, are expanding.

These changes will have direct implications – some good, some bad – for recreational fishers, who, in the United States alone, contributed nearly $700 million in revenue to state agencies through license, tag, stamp, and permit purchases in 2015. Annually, anglers spend about $25 billion on trips, gear, and equipment related to recreational fishing in U.S. freshwaters.

“The U.S. Geological Survey and partners are working to provide a fuller and more comprehensive picture of climate change impacts on North American fish for managers, scientists, and the public alike,” said Abigail Lynch, a lead author and fisheries biologist with the USGS National Climate Change and Wildlife Science Center.

The authors reviewed 31 studies across North America and Canada (see map) that document fish responses to climate change. The manuscripts describe the impacts of climate change to individual fish, populations, recreational fishers, and fisheries managers. One of the takeaway messages is that climate change effects on fish are rarely straightforward, and they affect warmwater and coldwater fish differently.

There’s lots more, after the jump. . . Continue reading

Climate change poses another threat to fish

We’ve posted previously about the climate change threats to the coral reefs sheltering the young of many of the fish compromising the main source of protein from many of the world’s nations.

Reefs provide a protective environment the fry of many fish species.

Now comes word of another climate change threat to developing young fish species.

From the University of Adelaide:

A common close partnership which sees baby fish sheltering from predators among the poisonous tentacles of jellyfish will be harmed under predicted ocean acidification, a new University of Adelaide study has found.

Published today in the journal Proceedings of the Royal Society B, the researchers say that modification of this baby fish-jellyfish symbiotic relationship is likely to lead to higher mortality among the affected fish species which include some of the common commercial fish. A well-known example of marine symbiosis is the relationship between anemones and clown-fish, popularised in the animated movie, Finding Nemo.

“These intricate, interdependent relationships between different species─symbioses─are common in both the marine and terrestrial environments,” says study leader Associate Professor Ivan Nagelkerken, in the University of Adelaide’s Environment Institute.

“But, apart from the well-known relationship between coral and microalgae and what happens during a bleaching event, little is known about how climate change and predicted ocean acidification will affect such relationships.

“This is the first study that demonstrates how climate change will disturb such a symbiotic relationship between two animals that interact closely for survival.”

The juvenile fish of about 80 different species, including important commercial varieties such as pollock, jacks and trevallies, form symbiotic relationships with jellyfish.

The jellyfish blooms are an ideal protective habitat for the baby fish, which would otherwise be unprotected in the open oceans where they are at high risk of being eaten by bigger fish and other marine life. Only one species of fish has known immunity to the jellyfish venom. Somehow the baby fish avoid the poisonous tentacles of the jellyfish while swimming among them, while other species stay well away.

The relationship is not straightforward however – sometimes the jellyfish will eat the baby fish. Despite this, the survival odds of the baby fish seem to be increased when sheltering with the jellyfish.

The researchers studied the actions of juvenile fish in an aquarium under high CO2 conditions. Compared to the control group, they spent much less time with the jellyfish host (about three times less), while only 63% (compared to 86%) initiated any relationship at all.

The research is in collaboration with Associate Professor Kylie Pitt at Griffith University. “Shelter is not widely available in open water so juvenile fish rely on the jellyfish for protection against predators,” says Associate Professor Pitt. “As shelter providers, the jellyfish could play a role in enhancing the populations of these fish species. Changing ocean conditions are likely to have significant negative impacts on this relationship and therefore, fish populations.”

Climate change threatens Antarctica’s penguins

Each colored circle represents a colonies’ current population trend. The black dashed line separates West Antarctic Peninsula (WAP) from continental Adélie penguin colonies. Bare rock () locations around the coastline and light to dark blue represents shallow to deep bathymetry modified from Cimino et al.

BLOG Caption

The Antarctic’s population of penguins, those flightless birds so beloved of children and animators everywhere, are imploding, threatening to number the creatures among the victims of climate change.

From the University of Delaware:

It’s a big question: how is climate change in Antarctica affecting Adélie penguins?

Climate has influenced the distribution patterns of Adélie penguins across Antarctica for millions of years. The geologic record tells us that as glaciers expanded and covered Adélie breeding habitats with ice, penguin colonies were abandoned. When the glaciers melted during warming periods, this warming positively affected the Adélie penguins, allowing them to return to their rocky breeding grounds.

But now, University of Delaware scientists and colleagues report that this beneficial warming may have reached its tipping point.

In a paper published today in Scientific Reports [open source], the researchers project that approximately 30 percent of current Adélie colonies may be in decline by 2060 and approximately 60 percent may be in decline by 2099.

“It is only in recent decades that we know Adélie penguins population declines are associated with warming, which suggests that many regions of Antarctica have warmed too much and that further warming is no longer positive for the species,” said the paper’s lead author Megan Cimino, who earned her doctoral degree at UD in May.

Co-authors on the work include Matthew Oliver, principal investigator on the project and Patricia and Charles Robertson Professor of Marine Science and Policy in UD’s College of Earth, Ocean, and Environment; Heather J. Lynch, assistant professor in the Department of Ecology and Evolution at Stony Brook University; and Vincent S. Saba, a research fishery biologist with the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service.

Declining populations

The Adélie penguin is a species that breeds around the entire Antarctic continent. The species is experiencing population declines along the West Antarctic Peninsula (WAP), which is one of the most rapidly warming places on Earth, while Adélie populations in other areas around the continent where the climate is stable or even cooling remain steady or increasing.

There’s more, after the jump. . .

Continue reading

California burning, images captured from space

While Donald Trump insists that California’s near-epochal drought is but a myth, it ain’t necessarily so.

Indeed, the state is tinder dry.

From NASA’s Earth Observatory:

BLOG Cal fire

More form NASA:

A wildfire burning northeast of Bakersfield, California, is the state’s largest so far in 2016, according to news reports. It has also been called the season’s a most destructive fire. As of June 27, the Erskine fire had scorched 18,368 hectares (45,388 acres), destroyed at least 250 structures, and was responsible for at least two deaths.

The top image shows the region at 3:34 a.m. Pacific Time on June 26, 2016. It was acquired with the day-night band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite. The DNB can detect relatively dim signals such as city lights and reflected moonlight. In this case it also shows the glow of wildfire.

The second image shows the fire later that same day. This natural-color image was acquired with the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA’s Aqua satellite. Red outlines indicate hot spots where MODIS detected warm surface temperatures associated with fires. Winds carried smoke from the fire northward.

The fire first ignited on June 23 due to a yet-unknown cause. On the date these images were acquired, the fire had burned 17,588 hectares (43,460 acres). As of June 27, the fire was 40 percent contained and continued to pose a threat to structures.

According to the National Interagency Fire Center, above normal fire potential is expected to expand into the Sierras and central coast region of California as summer progresses. According to the outlook: “The highest potential may be over the Sierra Foothills where a severe, multiyear drought has exacted a toll on the vegetation of the area.”

And there will be more to come, thanks to a massive die-off of California’s pine, fir, and cedar forests.

From United Press International:

California’s climate has always been hospitable to fire – it comes with the territory. But add five years of drought, a bark beetle blight killing trees by the millions and rising temperatures, and it’s a recipe for disaster.

“We are seeing the compounded effects of climate change that includes five consecutive years of drought and rising mean temperatures across the West – last year was the hottest year on record,” said Janet Upton, deputy director of communications at the California Department of Forestry and Fire Protection. “All that is trending to a more flammable California.”

Last week, the U.S. Forest Service reported that 26 million trees had died in six counties in the southern Sierra Nevada since October. Adding in an estimated 40 million dead trees counted since October 2010, it brings the statewide tree mortality to at least 66 million in less than six years.

High rates of tree mortality are being driven by bark beetles in combination with the state’s drought. Like fire, bark beetles are a natural part of the state’s ecology and a way for nature to weed out the weak and keep forests healthy. But when the trees suffer from drought, they no longer have their natural defense mechanism to fight off bark beetles. “Trees draw up moisture and push the beetle out,” said Upton. “With the drought, they couldn’t draw the moisture needed to do that.” And that has led to a bark beetle explosion – to epidemic levels.

Hardest hit so far has been the southern Sierra. “We identified six high-hazard counties and now we’ve added four more,” said Upton. The bark beetle blight is marching to the north.