Tag Archives: global warming

NASA and NOAA Agree: 2014 Was Hottest Year On Record

Though it might be hard to believe right now since the Northern Hemisphere is currently experiencing the coldest part of winter, our average global temperatures are increasing at a worrying rate. NASA and NOAA have analyzed the data independently of one another and yet have arrived at the same conclusion: 2014 is the warmest year on record since 1880. This is the 38th consecutive year with above average surface temperatures. The dataset has been released by NASA’s Goddard Institute for Space Studies (GISS).

“NASA is at the forefront of the scientific investigation of the dynamics of the Earth’s climate on a global scale,” NASA’s John Grunsfeld said in a press release. “The observed long-term warming trend and the ranking of 2014 as the warmest year on record reinforces the importance for NASA to study Earth as a complete system, and particularly to understand the role and impacts of human activity.”

Surface temperatures in 2014 averaged 0.8° C (1.4° F) warmer than 1880. This doesn’t mean that 1880 was a particularly hot year; it’s just where the instrumental record begins. It might not seem like a significant increase, but it can have an incredible impact on the environment. This increase has been largely attributed to carbon dioxide released into the atmosphere due to human activity.

Those living in the Midwest or East Coast of the United States will remember last year’s Polar Vortex, which brought extreme winter weather to hundreds of millions of people. However, other parts of the country experienced record-setting temperatures during the summer, offsetting the cold experienced during the winter.

Overall, the planet has been growing increasingly warmer for several decades. Variations in weather patterns have created slight cooling periods, but looking at the larger picture shows that temperatures are definitely looking up, and not in a good way. In fact, nine out of the 10 warmest years since the record began have happened after 2000. The exception is 1998, due to the intense effects of El Niño. 2014 was not affected by El Niño.

Image credit: NASA, Hansen et al. (2010)

“This is the latest in a series of warm years, in a series of warm decades. While the ranking of individual years can be affected by chaotic weather patterns, the long-term trends are attributable to drivers of climate change that right now are dominated by human emissions of greenhouse gases,” noted Gavin Schmidt, GISS Director.

Though NASA and NOAA have agreed that 2014 was the warmest year since the Industrial Revolution, they used different methods for data collection. Researchers at GISS combined data from 6,300 weather stations to get land temperatures, while ocean temps were retrieved via ships, buoys, and from the Antarctic. NOAA’s conclusion also came from data collected by ships and buoys, though it made use of satellite and radar data as well.



Read more: http://www.iflscience.com/environment/nasa-and-noaa-agree-2014-was-hottest-year-record

Deep Ancient Water Is Stopping The Antarctic Ocean From Warming

The waters around the Antarctic may be one of the last places on Earth to feel the effects of man-made climate change. According to researchers at the University of Washington (UW) and the Massachusetts Institute of Technology (MIT), ancient seawater upwelling from the depths explainwhy the sea surface has remained roughly the same temperature while most of the planet has experienced temperature rises.

Using a combination of observations from floating ocean current trackers and cutting-edge computer simulations, the new Nature Geoscience study shows that this centuries-old seawater hasnt been to the surface since the dawn of the Industrial Revolution. Although the cooler waters around the Antarctic were previously blamed on ocean currents drawing sea surface heat down to the depths, it appears that cold water yet to experience the newly-warmed atmosphere is currently rising up to the surface.

With rising carbon dioxide you would expect more warming at both poles, but we only see it at one of the poles, so something else must be going on, the studys lead author Kyle Armour, a UW assistant professor of oceanography and of atmospheric sciences, said in a statement. We show that it’s for really simple reasons, andocean currentsare the hero here.

Observed warming over the past 50 years, as measured in degrees Celsius per decade. Its clear that the Southern Ocean has warmed by only a fraction, and it appears ocean currents are to blame for this unusual refrigeration mechanism. Kyle Armour/UW

Seawater from the deepest depths of the worlds oceans upwell at different times, and they do so when they become less dense than the water above them. This can happen for many reasons, including a reduction in salt concentrationor an influx of heat at depth, both of which make them more buoyant. On occasion, there can be a mechanical driver of seawater upwelling, such as persistent winds.

This is whats happening in the Southern Ocean, where extremely powerful westerly winds keep pushing warming surface water northwards; this gives the deeper, older water space to upwell into. The novel aspect of the waters here is that they have to upwell from depths of several thousand meters, far beyond the depths that most other oceanic currents reach. This means that it takes them an incredibly long time to reach the surface and interact with the atmosphere.

According to the models run by the team, the water only just beginning to reach the surface off the coast of Antarctica last experienced the Earths atmosphere centuries ago in the North Atlantic, before any serious man-made climate change had the chance to significantly heat it up. In fact, their simulations show that the oceanic currents that have experienced the most warming appear to be gathering at the North Pole, which also partly explains why Arctic sea ice is disintegrating so rapidly.

When we hear the term ‘global warming,’ we think of warming everywhere at the same rate, Armour added. We are moving away from this idea and more toward the idea of regional patterns of warming, which are strongly shaped by ocean currents.

The fact that Antarctic sea ice has been growing just as the Arctics has been disintegrating has baffled scientists for some time; irritatingly, this discrepancy is often cited by climate change deniers as proof that climatologists dont know what theyre talking about. It was only a matter of time before several explanations emerged, and this new study represents one of two corroborating theories helping to explain why the sea ice around Antarctica has been unexpectedly growing.

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Greenland’s Ice Sheet Is Melting Ridiculously Early

Greenlands colossal ice sheet is melting early, and guess what were to blame. According to the climatologists at the Danish Meteorological Institute (DMI), 12 percent of the ice sheets surface area is already showing signs of melting, and this is, without a doubt, due to unseasonably warm temperatures and rain induced by man-made climate change.

This degree of melting would be expected in any scenario at the onset of summer, but is completely unprecedented halfway through April. In fact, this finding means that it has destroyed the record for early Greenland melting by over three weeks. Even in 2012, when 95 percent of the ice sheet was melting, it still began later in the year.

It’s disturbing, Peter Langen, a climatologist at DMI, said in a statement. Something like this wipes out all kinds of records, you can’t help but go this could be a sign of things we’re going to see more often in the future.

This frigid mass which at 1.7 million square kilometers (656,000 square miles)makes it roughly the same size as Mexico melts and refreezes on an annual summer-winter cycle. However, what is currently being observed can only be due to the year-on-year increases in sea surface, land and atmospheric temperatures.

The capital of this Danish territory, Nuuk, reached 16.6C (62F) this Monday, crushing the previous high-temperature record for that month by 3.5C (6.5F). Further inland, temperatures were warmer than San Francisco.

Left: Maps showing the unprecedented early melting extent (red) along the Greenland Ice Sheet. Right: Ice melt as a percentage of total area. The gray-shaded area denotes the average melt for each month from 1990-2013; the blue line marks the current melting extent. DMI

As in the summer months, higher temperatures cause the top of the ice sheet to melt, while warmer waves chip away at the baseof icy dams, keeping land-based ice from falling into the ocean. A warmer climate also encourages greater rates of precipitation; consequently, pools of warmer water delivered by increased rainfall help to break apart huge masses of ice.

All of these mechanisms conspire to disintegrate Greenlands Ice Sheet and thanks to man-made climate change, things are happening fair earlier, and far worse, than expected. The Greenland Ice Sheet has shed about 3.5 billion tonnes (3.9 billion tons) of ice since 2003, and this early April melting could be a sign that the annual rate of ice shedding is due to increase.

Things are getting more extreme and they’re getting more common, noted NASA ice scientist Walt Meier. One freakish thing every once in a while you might expect. But we’re getting these things more often and that’s an indication of climate change.

Unlike the collapse of ice shelves, the melting of ice sheets directly and immediately contributes to sea level rise. Within the next century, Greenlands melting is set to contribute at least 6meters (20 feet) in sea level rise.

Studies confirmthat the terrestrial advance of the oceans can only be halted by 2100 if the Paris climate agreement warming target of 2C (3.6F) is adhered to; otherwise, researchers have all but confirmed that it will doom coastal metropolises like New York City and Miami to eventual oblivion.

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Cloud Contributions Could Make Global Warming Even Worse

It has been a bad fortnight for climate change news, from the heat-induced devastationof coral reefs to warnings that sea levels could rise much faster than we thought. This unfortunate pattern continues with the announcement that we have been miscalculating the feedback between global warming and cloud formation, suggesting most climate projections have been too optimistic.

Clouds are among the hardest aspects to incorporate into models of how the atmosphere will respond to inputs such as increased carbon dioxide. This is because not all clouds behave alike. We know that the warming induced by carbon dioxide emissions will cause the atmosphere to hold more water vapor, leading to more clouds. However, with high clouds warming the planetand lower-altitude clouds havinga cooling effect, it is hard to know which will dominate.

Yale University graduate student Ivy Tanhas looked at clouds from both sides nowand her conclusions, published in Science,are disturbing. Sadly, it turns out they won’t block the Sun nearly as much as we would like.

Clouds are formed from ice crystals and supercooled liquid droplets, and the balance between these components is important. For a fixed amount of cloud water, spherical liquid droplets tend to be smaller in size and also to outnumber ice crystals, because ice nuclei are relatively scarce in Earths atmosphere in comparison to cloud condensation nuclei, Tan noted in the paper. As a consequence, clouds that consist of a higher fraction of liquid are optically thicker and hence more reflective of sunlight.

Tan pointed to previous workthat showed certain clouds contain fewer crystals and more droplets than previously realized. The crucial question is how this will change in a world where the atmosphere contains both more carbon dioxide and more heat.

Using 79 months of data from NASA’s Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) satellite observations, Tan concluded that models have over-estimated the current rate of ice crystal growth. When she ran what she sees as more realistic processes through climate models, the results were terrifying:A model that previously predicted 4.0C (7.2F) of warming now produced 5.0to5.3C (9.0to9.5F).

Calin Tatu/Shutterstock

An initial doubling of CO2 concentrations causes the entire troposphere to deepen, the paper reported. This in turn increases the altitude at which a particular temperature is reached, with consequent effects on the crystal/droplet ratio.

The impact on cloud formation is greatest over the Southern Ocean, the paper noted. However, additional heat captured there will make its way around the entire globe.

The paper expresses confidence thatshould the low [ice formation] bias be eliminated from global climate models, the estimation of temperatures for a particular concentration of carbon dioxide will increase. Whether the extra warming will be as large as Tan’s initial estimates remains to be seen; the paper acknowledges that other models may be affected by different amounts.

However, even if the additional warming turns out to be only half as large as Tan’s model shows, our problems just got bigger.

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Read more: http://www.iflscience.com/environment/cloud-contributions-could-make-global-warming-even-worse

2015 Was The Hottest Year Since Records Began By An Enormous Margin

Climatologists have been predicting it for the last few months, but with all the data now analyzed, its official: 2015 was the hottest year since records began in 1850. The news comes after three of the worlds major organizationshave concluded their independent analysis of their climate data and unanimously drewthe same conclusion. This is the second year in a row that global temperatures have broken the record, and if current trends continue, then it looks like 2016 will make it a third.

The results were released by NASA, the National Oceanic and Atmospheric Administration (NOAA), and the U.K. Met Office, who all agree the data showaworrying trend. Althoughthe heads of state all gathered in Paris at the end of last year to agree to limit global warming to below 2C (3.2F), while striving to prevent average temperatures to rise above 1.5C (2.7F), it may already be too late for that. 2015 was a record-breaking year for our climate. Global mean temperatures reached 1C [1.6F] above pre-industrial levels for the first time and the year’s average global temperature was the highest ever recorded, says Peter Stott, from the Met Office in the U.K.

The consequences of the mercury creeping ever higher have already started to be felt across the globe, although due to nuances in the weather and climate patterns, some places are being hit harder than others. India, for example, experienced the second-worst heat wave in the countrys history last year, claiming more than 2,300 lives when temperatures reached up to an unforgiving 48C (118F) in some cities. China, on the other hand, was severely hit by flooding, costing the nation an estimated $25 billion (16.6 billion) and affecting 75 million people.

This all occurred even before we take into account what could be one of the worst El Nio events the world has seen in a century, which has only acted to exasperate what was already set to be the hottest year. With its continuation into 2016, its putting things in place to make this year equally warm, if not hotter. Such a large El Nio not only impacts the Americas, playing a hand in the flooding in South America and the record warm December across much of the United States, but might also create problems as far away as Africa, causing droughts and potentially famine.

Normally when heat records are set, they are reached gradually, but this year saw the average global temperaturejump by a staggering quarter of a degree fahrenheit, adding to the thoughts that temperatures are rising at an increasingly rapid rate. According to the Mets figures, 2015 was a whopping 0.75C higher than the average from 1961 to 1990. While there are slight discrepancies between the meteorological organizations due to differences in methods and data sets, they all converge on the overall outcomes.

Climate change is the challenge of our generation, and NASAs vital work on this important issue affects every person on Earth, explains Charles Bolden, NASAs administrator, in a statement. Todays announcement not only underscores how critical NASAs Earth observation program is, it is a key data point that should make policy makers stand up and take noticenow is the time to act on climate.

Read more: http://www.iflscience.com/environment/2015-officially-hottest-year-records-began

Greenland’s Meltwater Rivers Are The Largest Contributor to Rising Sea Levels

Over 80% of Greenland’s surface is covered with ice, which features vast crystal blue rivers of meltwater. As gorgeous as the scenery is, a new study has indicated that meltwater from this ice sheet is the largest contributor to rising sea levels. The water from the streams drains more water into the ocean than the combination of Greenland’s meltwater lakes and chunks of ice that break off and fall in, which were previously believed to play the biggest role in rising sea levels. Laurence Smith of UCLA served as the lead author of the paper, which was published in the Proceedings of the National Academy of Sciences.

“It’s the world’s biggest water park, with magnificent and beautiful — but deadly — rushing blue rivers cutting canyons into the ice,” Smith said in a press release, describing Greenland’s topography. 

During a six-day-long expedition in July of 2012, the research team studied these streams using a variety of equipment, including GPS-buoys, a drone boat, and extensive satellite imaging. These measured the location, length, and depth of the streams, as well as how much light was reflected off the water. The expedition was well-timed, as the amount of meltwater in 2012 was one of the highest of the last 700 years.

“It was a real preview of just how quickly that ice sheet can melt and the meltwater can escape,” Smith said.

They found that as the ice melts on the surface, it forms swift-moving rivers that quickly ferry the water away. The water then drains into an opening in the ice called a moulin, travels through the inside of the ice sheet, and emerges underneath, where it can then flow out into the ocean at a rate of 55,000 to 61,000 cubic feet per second. Before this study, not much was known about the ultimate fate of the meltwater rivers. It hadn’t been clear whether all of the meltwater drained into the ocean, or if some remained inside the ice. Though nearly all of the water in the 523 streams drained off of the surface, there does seem to be an unspecified amount getting hung up within the ice.

This study also examined the Isortoq River, which is an integral component of the IPCC’s MAR climate model and drains 20% of all Greenland’s meltwater. The river’s output was over 25% lower than previously believed, indicating that some gets held within the ice. Having a better understanding of the river’s true output and contribution to sea level will improve future climate models, though further research is necessary to determine exactly how much water stays inside the ice.

“If we can get better estimates, then we can have better projections for the extent and the impact of global warming,” added co-author Marco Tedesco of City College of New York. “Greenland is really the big player for sea level rise in the future, so improving climate models is extremely crucial.”

The team has dedicated the research to the memory of co-author Alberto Behar, who was a researcher at Jet Propulsion Laboratory and Arizona State University. He designed the drone boat used by the research team for data collection. Behar died on January 9 in a small plane crash in Los Angeles.

“The measurements we collected would not have been possible without the truly innovative instruments designed by Alberto Behar, and his steady hand during some very trying conditions in the field. The scientific outcomes of this study can be traced directly to him,” Smith told NASA.



Read more: http://www.iflscience.com/environment/greenland-s-meltwater-rivers-are-largest-contributor-rising-sea-levels

Climate Change Is Synchronizing Forest Growth Across Vastly Different Biomes

Researchers analyzing over a centurys worth of growth in tree rings have revealed that climate change is synchronizing forest growth across vast swaths of dramatically different habitats from frigid central Siberia to the mild, Mediterranean climes of Spain. The findings are published in Proceedings of the National Academy of Sciences this week.

Forests play a huge role in the carbon balance of the planets terrestrial ecosystems, but we have yet to figure out whether climate warming will result in longer, more effective growing seasons or worsen droughts, increase heat stress, and reduce productivity.

To better understand how climate change and increasing variability affect tree growth across continents,Jordi Voltasfrom the University of Lleida in Spainand colleagues examined 120-year tree-ring chronologies spanning 1890 through 2009. They studiedsix species of conifers (or evergreens) in two contrasting Eurasian settings: 45 chronologies from boreal forests in Siberia where tree growth is constrained by the cold, and 48 chronologies from Spain where Mediterranean forests are water-limited. Siberia has a prolonged cold season, large temperature variations throughout the year, and moderate amounts of precipitation. Spain, on the other hand, has mild to cool, wet winters and droughts in the summertime.

Spatial synchrony in tree growth refers to the extent of comparable changes in ring-width patterns among geographically disjoined tree populations. These tree ring samples reveal that synchrony in annual growth patterns peaked in the 21st century for these disparate biomes. Their response to climate change increased growth synchrony among forest stands separated by a thousand kilometers to levels wed expect of those within the same stand.

Enhanced synchrony is becoming a widespread, although regionally dependent, phenomenon related to warmer springs and increased temperature variability in high latitudes and to warmer winters and drier growing seasons in mid-latitudes, the team writes. In boreal forests, wood formation is getting an earlier start, for example, while Mediterranean forests are experiencing an advanced onset of growth.

High temperatures, as well as increasingly intense climate extremes, exert about as much influence as local drivers of tree growth such as topography, nutrient availability, and competition among trees. One day, large-scale synchrony may overwhelm regional differences.

Read more: http://www.iflscience.com/plants-and-animals/climate-change-synchronizing-forest-growth-across-vastly-different-biomes

Study Claims Antarctic Ice Is Growing, But Net Gain Will Reverse In Decades

A group of scientists has claimed that some regions of Antarctica are gaining ice as a result of snowfall 10,000 years ago but the rate is decreasing such that in mere decades, it may shift to an annual net loss of ice.

In the study, published in the Journal of Glaciology and led by Jay Zwally of the NASA Goddard Space Flight Center, it’s explained that the rate of increase inland compared to decrease at the coastal regions is resulting in a net gain. This is incontrast to the Intergovernmental Panel on Climate Changes (IPCC)2013 report, which says the loss is already happening.

“We’re essentially in agreement with other studies that show an increase in ice discharge in the Antarctic Peninsula and the Thwaites and Pine Island region of west Antarctica,” Zwally said in astatement. Our main disagreement is for east Antarctica and the interior of west Antarctica there, we see an ice gain that exceeds the losses in the other areas.

Zwally and his co-authors compared satellite observations of the height of the Antarctic ice sheets from 1992 to 2001 and 2003 to 2008. During the earlier period the continent put on a net 112 billion tons of ice a year, plus or minus 61 billion tons. After 2003, however, the paper reports gains of 136 billion tons per yearin eastern Antarctica and 72 billion tonsin four drainage systemsin westernAntarctic that exceed losses of 97 billion tons a yearfrom three coastal drainage systems and 29 billion tonsfrom the Antarctic Peninsula.

The net effect is an extra82 billion tons of ice a year from 2003 to2008, with an uncertainty of 25 billion tons, significantly less than the annual gain between 1992 and 2001.

Previousstudies attributed rises in Antarcticas central plateaus to recent snowfalls yet to condense to solid ice. However, Zwally found evidence these areas have been building up for a millennia, and the recent seasons have not been particularly snowy.

At the end of the last Ice Age, the air became warmer and carried more moisture across the continent, doubling the amount of snow dropped on the ice sheet, Zwallysaid.

The IPCC’s 2013 report,summarising numerous studies, concluded that overall Antarctica is losing ice to the oceans. This lateststudy, however, suggests that something else has causedthe well established rise in oceanheight over the last two decades,and that when the reversal of ice growth does eventually happen, the rise could be accelerated.

If the 0.27 millimeters [0.01 inches] per year of sea level rise attributed to Antarctica in the IPCC report is not really coming from Antarctica, there must be some other contribution to sea level rise that is not accounted for, said Zwally.

Indeed, the 30 billion tonreduction in annual ice accumulation between the two periods is unlikely to be a fluke. Instead, the authors expect the loss of ice from coastal areas to accelerate until, in roughly 20 years’ time, it overtakes the build-up inland.

The new study highlights the difficulties of measuring the small changes in ice height happening in East Antarctica, Ben Smith, a glaciologist with the University of Washington in Seattle who was not involved in Zwallys study, added in the statement.

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Polar Bears Face Starvation And Cub Loss Due To Sea Ice Loss

The future is not looking bright for polar bears living in Canada’s Arctic islands. If the current climate trend continues to the end of the century, sea ice decline will mean that many areas are no longer able to support polar bears, a depressing new study has found. With an absence of ice for several months a year, polar bears may face losing their cubs and starvation, leaving a rather bleak outlook for this population. The work has been published in the open access journal PLOS ONE.

The world is warming up, and it’s having devastating impacts on ecosystems. Among those areas feeling the heat is the Arctic, which has lost an average of 54,000 square kilometers (20,800 square miles) of ice every year since the late 1970s. This year, the sea ice extent in this region was the sixth lowest on record.

These losses dramatically change Arctic marine ecosystems, making marine mammals particularly susceptible to the effects of rising temperatures. Polar bears, in particular, are very sensitive to losses in sea ice because it serves as a platform for hunting seals and mating. If they can’t get enough food in their bellies, they won’t have sufficient energy reserves to survive the lean months. Furthermore, climate change may mean that some seal habitats are no longer viable, further reducing the availability of food.

To gain a better understanding of how climate change may affect polar bear populations, researchers from the University of Alberta used a regionally focused climate model to project sea ice changes in the Canadian Arctic Archipelago. This area is home to a quarter of the world’s polar bears, despite only covering 9% of the global polar bear range. Currently, sea ice is constantly present throughout the year.

They predict that towards the end of the century, the vast majority of the archipelago could experience early ice break up, which would leave regions ice-free for two to five months every year. This would force pregnant females to retreat to land early, which could interfere with births. By 2010, females may lose between 55 to 100% of their cubs.

Furthermore, because long ice-free periods mean that polar bears likely will not be able to eat sufficient amounts of food, up to 1 in 5 adult bears and even more young and old bears could starve each year.

Although it’s difficult to say whether these predictions are reliable, areas are already experiencing sharp declines in polar bear numbers. The southern Beaufort Sea, for example, experienced a 25 to 50% decline in abundance between 2001 and 2010. However, extinction is not necessarily looming as efforts to reduce greenhouse gas emissions could mean that sea ice loss could begin to slow down. 

[Via PLOS ONE, New Scientist, The Star and WWF]

Read more: http://www.iflscience.com/plants-and-animals/polar-bears-face-starvation-and-cub-loss-due-sea-ice-loss

NASA Just Completely Shut Down Climate Change Deniers On Facebook

Comment sections are always fun places, especially when impassioned issues are involved. But usually, the back and forthsof keyboard bashing quickly fadeinto the white noise of the Internet. So you know when NASA shows up in the comment section of a post about climate change to tell you youre wrong, its probably time to call it a day.

NASAs comments came after Bill Nyeposted a story about himselfasking a prominent climate change denier to put his money where his mouth is. Nye, the science guy, offered two $20,000 bets to leading climate change denier Marc Morano, during an interview Morano himself had requested, that this year will be in the top 10 hottest years on record and this decade will also be the hottest on record. Alas, Morana declined the wagers.

Unsurprisingly, Nye posting the story to his Facebook page created a rumble and summoned the keyboard-wielding trolls to the comments section below the article. Perhaps after a late-night binge on YouTube conspiracy videos, many people accused NASA of being a leading voice in promoting the scam of man-made climate change by skewing figures and lying to the public about its data. A few commenters also wrongly cited, or just simply made up, some previous claims of NASA.

In a rebuttal, theNASAClimate Change Facebook page begun commenting back in a cool, calm and bluntly straight-to-the-point fashion to set the record straight. They even brought charts and everything.


ImageCredits: Screenshots via Facebook

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