Climate Change Archives

October 10, 2013April 26, 2016 by Shannon Hall

Earth and Climate: Two Scenarios of Our Planet in 2100 AD

The Earth at night. What will it look like 100 years from now? Image credit: NASA-NOAA

The Earth is warming up.

Ocean temperatures are rising. Arctic sea ice is melting. Atmospheric carbon dioxide levels are growing. The oceans are becoming more acidic. The weather is already more extreme.

With the release of the fifth Assessment Report by the Intergovernmental Panel on Climate Change – a panel of more than 2,500 experts, more commonly known as the IPCC – it’s clear that climate change is very real. But it’s especially clear that we are the cause. If we don’t act now by taking vigorous action to reduce emissions the results will be catastrophic.

Toward the end of this 900-page report, the IPCC looked toward our future, focusing on the climate after the year 2100. Here, Universe Today, explores two extreme scenarios for the Earth by 2100.

1.) Embracing the Challenges of Climate Change

The conclusions reached by climate scientists at the end of the 21st Century were undeniable. We embraced climate change by investing heavily in renewable energies. Both large-scale companies and individuals bought energy drawn from the sunlight, wind, and geothermal heat.

Homes across the world became more sustainable. Their total square feet shrunk, as home owners learned to live with less. It was not uncommon to dress a roof with plants or solar panels. Even the layout of homes changed. They rested partially underground, taking advantage of geothermal heat, and faced South (in the case of the Northern hemisphere) to take advantage of the warm sunlight.

We also embraced geoengineering technologies. We added artificial clouds to our atmosphere, which reflected sunlight, and built towers to collect greenhouse gas emissions. The gases are now trapped deep underground. Our goal was not only to slow the process of climate change, but to stop it, and quite possibly reverse it.

We now eat far less meat than we did in the early 21st Century to cut the emissions generated from livestock farming. Pastures have been replaced with booming forests – helping to absorb CO2. We also eat more locally.

The world followed in China’s footsteps and restricted couples to a certain number of children, reducing our overall population.

We live in small compact cities where we drive hybrid cars and take public transport to work. Carbon offsets must be purchased when taking long trips. Most families vacation in their own backyard – exploring all that nature has to offer in the nearby vicinity.

We viewed climate change as an exciting opportunity to embrace the needs of our environment. We now live much simpler lives and the census shows that our overall intelligence and happiness is much higher than it was a century ago.

2.) The Point of No Return

We simply didn’t want to face the facts. We live in a global economy with a population that has increased significantly over the last century. Most of our energy still comes from fossil fuels. We never invested in renewable energies.

We measure our happiness based on the cars we drive, the number of material possessions we can cram into our large homes, and how often we travel the globe.

The world is, on average, 9 degrees warmer. The entire arctic has melted. Ocean levels have risen by over a meter – flooding coastal communities across the world. Millions have been left homeless.

Our weather is extreme. Hurricanes, tornadoes, fires, floods, draughts, and earthquakes kill hundreds of thousands per year. Climate change has devastated food production and water supplies.

Air quality is much poorer across the world. Due to haze, it is perfectly safe to look at the sun directly. We can only see a third of the stars visible a century ago.

We have triggered various tipping points. The thawing of permafrost released further CO2 and methane. Large areas of the planet are becoming uninhabitable. Our efforts are working toward damage control only. We fear that it may be too late.

Climate change is still in our hands, but we have to act now.

The fifth Assessment Report by the IPCC may be found here. Emphasis in this article may be found in the long term climate change section, as well as descriptions published by the IPCC in 2000.

October 2, 2013April 26, 2016 by Elizabeth Howell

Could The U.S. Government Shutdown Hammer Earth and Mars Missions?

Artist's conception of the Mars 2020 rover. Credit: NASA

As Day 2 of the United States government shutdown continues, some short-term effects are already in evidence when it comes to Earth and space.

Most of the NASA and National Oceanic and Atmospheric Administration (NOAA) websites are offline. Social media updates are silent. At NASA, 97% of agency employees are off work and media reports indicate that 55% of NOAA’s employees are furloughed.

If the shutdown lasts for very long, however, long-term programs could feel the pain. This includes a couple of Mars missions NASA is developing, as well as Earth-based climate research and satellite observation from NOAA.

Mars 2020

A twin rover to Mars Curiosity, called Mars 2020 for now, is expected to leave for the Red Planet in 2020 and do investigations into past life and habitability. Planning is still in the early stages, but an announcement of opportunity for science investigators was supposed to happen on Oct. 8. Notices of intent were due Oct. 15.

“The preproposal conference, scheduled for 10/8, may be rescheduled and the due date for NOIs (currently 10/15) could be delayed, if the government is still shut down closer to those dates,” NASA officials wrote in an update before the shutdown on Monday.

MAVEN

As widely reported yesterday, the next Mars orbiter from NASA is expected to lift off from Earth on Nov. 18. Now, however, preparatory work has ceased and there is some concern from team members that it will miss the launch window, which extends into December. At worst, this means MAVEN’s launch could be delayed until 2016, when the next opportunity opens.

“The hardware is being safed, meaning that it will be put into a known, stable, and safe state,” Bruce Jakosky, MAVEN’s principal investigator, told Universe Today‘s Ken Kremer yesterday. “We’ll turn back on when told that we can. We have some margin days built into our schedule.”

NOAA

As with NASA, NOAA is keeping up with mission-critical activities — which in their case, includes weather forecasting. Long-term climate research, however, is reportedly being shelved.

“For example, Harold Brooks, a top tornado researcher who works at the National Severe Storms Laboratory in Norman, Okla., reported his furlough notice on Facebook on Tuesday,” Climate Central wrote on Oct. 1. “Much of the staff at NOAA’s Earth Systems Research Lab and the Geophysical Fluid Dynamics Laboratory, except for positions related to maintaining computing resources, have also been furloughed. Those two labs are heavily involved in NOAA’s climate research programs.”

A view of Hurricane Irene taken by the GOES satellite at 2:55 p.m. Eastern Daylight Time on August 24, 2011. Credit: NASA

Observers are also worried that a lengthy shutdown could push back the time when new weather satellites become available. There have been multiple reports about a “weather satellite gap” coming in the United States as many of NOAA’s geostationary and polar-orbiting satellites are nearing the end of their expected lives. The Subcommittees on Oversight and Environment held hearings into this issue in September.

What’s still online?

These are some of the programs that are still happening at NASA and NOAA:

NASA:

Bare-bones management on programs such as the International Space Station and several robotic missions that are already in operation (such as the Lunar Atmosphere and Dust Environment Explorer (LADEE).
Certain missions are in critical phases that could be hurt if work stops, such as the James Webb Space Telescope, which is undergoing cryogenic testing on some of its instruments.
Several missions run out of the Jet Propulsion Laboratory and Applied Physics Laboratory are still running as usual, according to the Planetary Society, as these receive contract money from NASA; this means Mars Curiosity is still working, for example.
The Mars Reconnaissance Orbiter’s HiRISE camera is still snapping pictures, its Twitter account reported, which is positive given that it was intended to snap shots of Comet ISON during its closest approach to Mars yesterday.
The decades-long Landsat Earth observation program is still operating, according to The Atlantic, with data being sent back to Earth as usual. The difference is this information won’t be packaged as usual until government operations restart.

NOAA (all information according to this Department of Commerce document):

The Office of Oceanic and Atmospheric Research will keep 73 employees on board “to ensure continuity of crucial long-term historical climate records, and real-time regular research to support ongoing weather and air quality prediction services,” NOAA said.
184 employees will stay with the Environmental Satellite and Data Information Service for command and control of several satellites for NOAA and the Department of Defense.
474 employees will remain with the National Marine Fisheries Service. 174 are funded in another form besides appropriations. The others are a mix of law enforcement, fisheries management and property protection officials.
490 employees are with the Office of Marine and Aviation Operations for observational data collection related to weather forecasting.
173 employees are with the National Ocean Service. 17 are funded outside of appropriations, while the 156 remaining “are required to protect against imminent and significant threats to life and property by supporting safe maritime commerce in U.S. waters, including real-time water level data for ships entering U.S. ports, critical nautical chart updates, and accurate position information,” NOAA stated. Some are also monitoring marine health aspects such as algal blooms.
There are 19 IT-related employees and 20 employees providing support services.
The large bulk of employees still at work, 3,935 people, are with the National Weather Service to keep up weather forecasting.

There’s no word yet on when government employees could go back to work. Congress representatives are jousting over the implementation of a spending bill to keep the money flowing to government departments. One big issue: whether to include the Affordable Care Act, sometimes dubbed Obamacare, in the bill.

Another deadline is looming, too. Treasury Secretary Jack Lew has warned repeatedly that on Oct. 17, if the debt ceiling is not raised, the United States government may default on some financial obligations.

July 24, 2013December 23, 2015 by Nancy Atkinson

Podcast: Climate Change

When it comes to carbon dioxide, just a little goes a long way to warming the planet. Unfortunately, we’ve been dumping vast amounts into the atmosphere, recently passing 400 parts per million. Let’s look at the science of the greenhouse effect, and how it’s impacting our global climate.

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

“Climate Change” on the Astronomy Cast website, with shownotes and transcript.

And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout (usually recorded every Monday at 3 pm Eastern Time):

July 2, 2013December 23, 2015 by David Dickinson

Happy (or is it Merry?) Aphelion This Friday

Solar apparent size- perihelion versus aphelion 2012.

This 4^th of July weekend brings us one more reason to celebrate. On July 5^that approximately 11:00 AM EDT/15:00 UT, our fair planet Earth reaches aphelion, or its farthest point from the Sun at 1.0167 Astronomical Units (A.U.s) or 152,096,000 kilometres distant.

Though it may not seem it to northern hemisphere residents sizzling in the summer heat, we’re currently 3.3% farther from the Sun than our 147,098,290 kilometre (0.9833 A.U.) approach made in early January.

We thought it would be a fun project to capture this change. A common cry heard from denier circles as to scientific facts is “yeah, but have you ever SEEN it?” and in the case of the variation in distance between the Sun and the Earth from aphelion to perihelion, we can report that we have!

We typically observe the Sun in white light and hydrogen alpha using a standard rig and a Coronado Personal Solar Telescope on every clear day. We have two filtered rigs for white light- a glass Orion filter for our 8-inch Schmidt-Cassegrain, and a homemade Baader solar filter for our DSLR. We prefer the DSLR rig for ease of deployment. We’ve described in a previous post how to make a safe and effective solar observing rig using Baader solar film.

Our solar imaging rig. — Our primary solar imaging rig. A Nikon D60 DSLR with a 400mm lens + a 2x teleconverter and Baader solar filter. Very easy to employ!

We’ve been imaging the Sun daily for a few years as part of our effort to make a home-brewed “solar rotation and activity movie” of the entire solar cycle. We recently realized that we’ve imaged Sol very near aphelion and perihelion on previous years with this same fixed rig, and decided to check and see if we caught the apparent size variation of our nearest star. And sure enough, comparing the sizes of the two disks revealed a tiny but consistent variation.

It’s a common misconception that the seasons are due to our distance from the Sun. The insolation due to the 23.4° tilt of the rotational axis of the Earth is the dominant driving factor behind the seasons. (Don’t they still teach this in grade school? You’d be surprised at the things I’ve heard!) In the current epoch, a January perihelion and a July aphelion results in milder climatic summers in the northern hemisphere and more severe summers in the southern. The current difference in solar isolation between hemispheres due to eccentricity of Earth’s orbit is 6.8%.

The orbit of the Earth also currently has one of the lowest eccentricities (how far it deviates for circular) of the planets at 0.0167, or 1.67%. Only Neptune (1%) and Venus (0.68%) are “more circular.”

The orbital eccentricity of the Earth also oscillates over a 413,000 year period between 5.8% (about the same as Saturn) down to 0.5%. We’re currently at the low end of the scale, just below the mean value of 2.8%.

Variation in eccentricity is also coupled with other factors, such as the change in axial obliquity the precession of the line of apsides and the equinoxes to result in what are known as Milankovitch cycles. These variations in extremes play a role in the riddle of climate over hundreds of thousands of years. Climate change deniers like to point out that there are large natural cycles in the records, and they’re right – but in the wrong direction. Note that looking solely at variations in the climate due to Milankovitch cycles, we should be in a cooling trend right now. Against this backdrop, the signal of anthropogenic climate forcing and global dimming of albedo (which also masks warming via cloud cover and reflectivity) becomes even more ominous.

Aphelion can presently fall between July 2^nd at 20:00 UT (as it did last in 1960) and July 7^that 00:00 UT as it last did on 2007. The seemingly random variation is due to the position of the Earth with respect to the barycenter of the Earth-Moon system near the time of aphelion. The once every four year reset of the leap year (with the exception of the year 2000!) also plays a lesser role.

Perihelion and aphelion vs the solstices and equinoxes, an exagarated view. — Perihelion and aphelion vs the solstices and equinoxes, an exaggerated view. (Wikimedia Commons image under a 3.0 Unported Attribution-Share Alike license. Author Gothika/Doudoudou).

I love observing the Sun any time of year, as its face is constantly changing from day-to-day. There’s also no worrying about light pollution in the solar observing world, though we’ve noticed turbulence aloft (in the form of bad seeing) is an issue later in the day, especially in the summertime. The rotational axis of the Sun is also tipped by about 7.25° relative to the ecliptic, and will present its north pole at maximum tilt towards us on September 8th. And yes, it does seem strange to think in terms of “the north pole of the Sun…”

We’re also approaching the solar maximum through the 2013-2014 time frame, another reason to break out those solar scopes. This current Solar Cycle #24 has been off to a sputtering start, with the Sun active one week, and quiet the next. The last 2009 minimum was the quietest in a century, and there’s speculation that Cycle #25 may be missing all together.

And yes, the Moon also varies in its apparent size throughout its orbit as well, as hyped during last month’s perigee or Super Moon. Keep those posts handy- we’ve got one more Super Moon to endure this month on July 22^nd. The New Moon on July 8^th at 7:15UT/3:15 AM EDT will occur just 30 hours after apogee, and will hence be the “smallest New Moon” of 2013, with a lot less fanfare. Observers worldwide also have a shot at catching the slender crescent Moon on the evening of July 9^th. This lunation and the sighting of the crescent Moon also marks the start of the month of Ramadan on the Muslim calendar.

Be sure to observe the aphelion Sun (with proper protection of course!) It would be uber-cool to see a stitched together animation of the Sun “growing & shrinking” from aphelion to perihelion and back. We could also use a hip Internet-ready meme for the perihelion & aphelion Sun- perhaps a “MiniSol?” A recent pun from Dr Marco Langbroek laid claim to the moniker of “#SuperSun;” in time for next January’s perihelion;

Could a new trend be afoot?

March 26, 2013December 23, 2015 by Ken Kremer

NASA’s Operation IceBridge Surveys Greenland and Earth’s Polar Ice Sheets

NASA P-3B waits outside the hangar at Thule Air Base with the Greenland Ice sheet in the background. The aircraft is set to begin the 2013 season of NASA’s Operation IceBridge mission to survey Earth's polar ice sheets in unprecedented three-dimensional detail. The plane just arrived from NASA Wallops Flight Facility in Virginia - see my P-3B photos below. Credit: NASA/Goddard/Michael Studinger

NASA’s Operation IceBridge has begun the 2013 research season of Ice Science flights in Greenland and the Arctic to survey the regions ice sheets and land and sea ice using a specially equipped P-3B research aircraft from NASA’s Wallops Flight Facility in Wallops Island, Va.

Operation IceBridge began in 2009 as part of NASA’s six-year long effort to conduct the largest airborne survey of Earth’s polar ice ever flown.

The goal is to obtain an unprecedented three-dimensional, multi-instrument view of the behavior of Greenland, Arctic and Antarctic ice sheets, ice shelves and sea ice which have been undergoing rapid and dramatic changes and reductions.

“We’re starting to see how the whole ice sheet is changing,” said Michael Studinger, IceBridge project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md. “Thinning at the margins is now propagating to the interior.”

The P-3 exiting the hanger pre-flight in Thule. Credit: NASA

The airborne campaign was started in order to maintain a continuous record of measurements in changes in polar ice after NASA’s Earth orbiting ICESat (Ice, Cloud and Land Elevation Satellite) probe stopped collecting data in 2009.

ICESat-2 won’t be launched until 2016, so NASA’s IceBridge project and yearly P-3 airborne campaigns will fill in the science data gap in the interval.

The P-3B Orion just arrived from NASA’s Wallops Flight Facility in Virginia where I visited it before departure – see my P-3B photos herein.

NASA IceBridge P-3B research aircraft prepares for departure from runway at NASA Wallops Flight Facility in Virginia to Thule Air Base in Greenland. Credit: Ken Kremer (kenkremer.com)

IceBridge is operating out of airfields in Thule and Kangerlussuaq, Greenland, and Fairbanks, Alaska.

The P-3B survey flights over Greenland and the Arctic will continue until May. They are conducted over Antarctica during October and November.

A sunny view of the ramp at Thule Air Base, Greenland, shortly after the NASA P-3B research aircraft arrived on Mar. 18, 2013. Credit: NASA / Jim Yungel

The measurements collected by IceBridge instruments will characterize the annual changes in thickness of sea ice, glaciers, and ice sheets. The data are used to help predict how climate change affects Earth’s polar ice and the resulting rise in sea-levels.

Researchers with the U.S. Army Corps of Engineers are collaborating with the IceBridge project to collect snow depth measurements near Barrow , Alaska. High school science teachers from the US, Denmark and Greenland will fly along on the P-3B survey flights to learn about polar science.

NASA Wallops has a wide ranging research and development mission and is home to the Virginia launch pad for the new Antares/Cygnus commercial ISS resupply rocket set for its maiden launch in mid April 2013; detailed in see my new story – here.

Ken Kremer

Sea ice in the southern Beaufort Sea. Credit: NASA

IceBridge departing to Fairbanks to start their sea ice flights that will cover the Beauford and Chukchi seas - via the Laxon sea ice route for the transit. Credit: NASA — IceBridge departing to Fairbanks to start their sea ice flights that will cover the Beauford and Chukchi seas – via the Laxon sea ice route for the transit. Credit: NASA

September 17, 2012December 23, 2015 by Jason Major

Manhattan-Sized Ice Island Heads Out to Sea

An “ice island” that calved from the Petermann Glacier in July is seen by NASA satellite (MODIS/Terra)

Remember that enormous slab of ice that broke off Greenland’s Petermann Glacier back in July? It’s now on its way out to sea, a little bit smaller than it was a couple of months ago — but not much. At around 10 miles long and 4.6 miles across (16.25 x 7.5 km) this ice island is actually a bit shorter than Manhattan, but is fully twice as wide.

The image above was acquired on September 14 by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite.

Although the calving of this particular ice island isn’t thought to be a direct result of increasing global temperatures, climate change is thought to be a major factor in this year’s drop in Arctic sea ice extent, which is now below 4.00 million square kilometers (1.54 million square miles). Compared to September conditions in the 1980s and 1990s, this represents a 45% reduction in the area of the Arctic covered by sea ice.

Arctic sea ice extent data for June-July 2012 (NSIDC)

This year sea ice in the Arctic Ocean dropped below the previous all-time record, set in 2007. 2012 also marks the first time that there has been less than 4 million square kilometers (1.54 million square miles) of sea ice since satellite observations began in 1979.

The animation below, released today by the NOAA, shows the 2012 time-series of ice extent using data from the DMSP SSMI/S satellite sensor:

Is Earth Alive? Scientists Seek Sulfur For An Answer

Image of Earth taken by ESA's Rosetta spacecraft in 2009

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Researchers at the University of Maryland have discovered a way to identify and track sulfuric compounds in Earth’s marine environment, opening a path to either refute or support a decades-old hypothesis that our planet can be compared to a singular, self-regulating, living organism — a.k.a. the Gaia theory.

Proposed by scientists James Lovelock and Lynn Margulis in the 70s, the Gaia theory likens Earth to a self-supporting singular life form, similar to a cell. The theory claims that, rather than being merely a stage upon which life exists, life — in all forms — works to actively construct an Earthly environment in which it can thrive.

Although named after the Greek goddess of Earth, the Gaia theory is not so much about mythology or New Age mysticism as it is about biology, chemistry and geology — and how they all interact to make our world suitable for living things.

Once called the Gaia hypothesis, enough scientific cross-disciplinary support has since been discovered that it’s now commonly referred to as a theory.

800px-Diatoms_through_the_microscope — Marine phytoplankton -- like these diatoms -- may produce sulfur compounds that can be transmitted into the air, affecting climate. (NOAA image)

One facet of the Gaia theory is that sulfur compounds would be created by microscopic marine organisms — such as phytoplankton and algae — and these compounds could be transmitted into the air, and eventually (in some form) to the land, thus helping to support a sulfur cycle.

Sulfur is a key element in both organic and inorganic compounds. The tenth most abundant element in the Universe, sulfur is crucial to climate regulation — as well as life as we know it.

In particular, two sulfur compounds — dimethylsulfoniopropionate and its atmospherically-oxidized version, dimethylsulfide — are considered to be likely candidates for the products created by marine life. It’s these two compounds that UMD researcher Harry Oduro, along with geochemist and professor James Farquhar and marine biologist Kathryn Van Alstyne (of Western Washington University) have discovered a way to track across multiple environments, from sea to air to land, allowing scientists to trace which isotopes are coming from what sources.

“What Harry did in this research was to devise a way to isolate and measure the sulfur isotopic composition of these two sulfur compounds,” said Farquhar. “This was a very difficult measurement to do right, and his measurements revealed an unexpected variability in an isotopic signal that appears to be related to the way the sulfur is metabolized.”

The team’s research can be used to measure how the organisms are producing the compounds, under which circumstances and how they are ultimately affecting their — and our — environment in the process.

“The ability to do this could help us answer important climate questions, and ultimately better predict climate changes,” said Farquhar. “And it may even help us to better trace connections between dimethylsulfide emissions and sulfate aerosols, ultimately testing a coupling in the Gaia hypothesis.”

Whether or not Earth can be called a singular — or possibly even sentient — living organism of which all organisms are contributing members thereof may still be up for debate, but it is fairly well-accepted that life can shape and alter its own environment (and in the case of humans, often for the worse.) Research like this can help science determine just how far-reaching those alterations may be.

The study appears in this week’s Online Early Edition of the Proceedings of the National Academy of Sciences (PNAS).

Read more on the University of Maryland’s news page here.

April 25, 2012December 23, 2015 by Jason Major

Antarctica’s Ice Being Eaten Away From Below

The 820-foot-wide crack in Antarctica's Pine Island Glacier, seen from DC-8 during Operation IceBridge (Credit: NASA/DMS)

Data collected from a NASA ice-watching satellite reveal that the vast ice shelves extending from the shores of western Antarctica are being eaten away from underneath by ocean currents, which have been growing warmer even faster than the air above.

The animation above shows the circulation of ocean currents around the western Antarctic ice shelves. The shelf thickness is indicated by the color; red is thicker (greater than 550 meters), while blue is thinner (less than 200 meters).

Launched in January 2003, NASA’s ICESat (Ice, Cloud and land Elevation Satellite) studied the changing mass and thickness of Antarctica’s ice from its location in polar orbit. An international research team used over 4.5 million surface height measurements collected by ICESat’s GLAS (Geoscience Laser Altimeter System) instrument from Oct. 2005 to 2008. They concluded that 20 of the 54 shelves studied — nearly half — were losing thickness from underneath.

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Most of the melting ice shelves are located in west Antarctica, where the flow of inland glaciers to the sea has also been accelerating — an effect that can be compounded by thinning ice shelves which, when grounded to the offshore seabed, serve as dams to hold glaciers back.

Melting of ice by ocean currents can occur even when air temperature remains cold, maintaining a steady process of ice loss — and eventually increased sea level rise.

“We can lose an awful lot of ice to the sea without ever having summers warm enough to make the snow on top of the glaciers melt,” said Hamish Pritchard of the British Antarctic Survey in Cambridge and the study’s lead author . “The oceans can do all the work from below.”

The study also found that Antarctica’s winds are shifting in response to climate change.

“This has affected the strength and direction of ocean currents,” Pritchard said. “As a result warm water is funnelled beneath the floating ice. These studies and our new results suggest Antarctica’s glaciers are responding rapidly to a changing climate.”

ICESat completed operations in 2010 and was decommissioned in August of that year. Its successor ICESat-2 is anticipated to launch in 2016.

Read more on NASA’s news release here.

Animation credit: NASA/Goddard CGI Lab

April 6, 2012December 23, 2015 by Jason Major

1981 Climate Change Predictions Were Eerily Accurate

The disintegrated Wilkins Ice Shelf in April 2009. (Chelys/EOSnap)

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A paper published in the journal Science in August 1981 made several projections regarding future climate change and anthropogenic global warming based on manmade CO2 emissions. As it turns out, the authors’ projections have proven to be rather accurate — and their future is now our present.

The paper, written by a team of atmospheric physicists led by the now-controversial James Hansen at NASA’s Institute for Space Studies at Goddard Space Flight Center, was recently rediscovered by researchers Geert Jan van Oldenborgh and Rein Haarsma from the Royal Netherlands Meteorological Institute (KNMI). Taking a break from research due to illness, the scientists got a chance to look back through some older, overlooked publications.

“It turns out to be a very interesting read,” they noted in their blog on RealClimate.org.

Even though the paper was given 10 pages in Science, it covers a lot of advanced topics related to climate — indicating the level of knowledge known about climate science even at that time.

“The concepts and conclusions have not changed all that much,” van Oldenborgh and Haarsma note. “Hansen et al clearly indicate what was well known (all of which still stands today) and what was uncertain.”

Within the paper, several graphs note the growth of atmospheric carbon dioxide, both naturally occurring and manmade, and projected a future rise based on the continued use of fossil fuels by humans. Van Oldenborgh and Haarsma overlaid data gathered by NASA and KNMI in recent years and found that the projections made by Hansen et al. were pretty much spot-on.

If anything, the 1981 projections were “optimistic”.

Tglobal_giss_verification — Data from the GISS Land-Ocean Temperature Index fit rather closely with the 1981 projection (van Oldenborgh and Haarsma)

Hansen wrote in the original paper:

“The global temperature rose by 0.2ºC between the middle 1960’s and 1980, yielding a warming of 0.4ºC in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean rend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980’s. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climate zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage.”

Now here we are in 2012, looking down the barrel of the global warming gun Hansen and team had reported was there 31 years earlier. In fact, we’ve already seen most of the predicted effects take place.

“Drought-prone regions” are receiving less rainfall, the Antarctic ice has begun to crack and crumble and bowhead whales are using the Northwest Passage as a polar short-cut.

Icemelt_Alaska8 — The retreat of Pedersen Glacier in Alaska. Left: summer 1917. Right: summer 2005. Source: The Glacier Photograph Collection, National Snow and Ice Data Center/World Data Center for Glaciology.

And that’s not the only prediction that seems to have uncannily come true.

“In light of historical evidence that it takes several decades to complete a major change in fuel use, this makes large climate change almost inevitable,” Hansen et al wrote in anticipation of the difficulties of a global shift away from dependence on carbon dioxide-emitting fossil fuels.

“CO2 effects on climate may make full exploitation of coal resources undesirable,” the paper concludes. “An appropriate strategy may be to encourage energy conservation and develop alternative energy sources, while using fossil fuels as necessary during the next few decades.”

(Watch a TED talk by James Hansen on “Why I Must Speak Out About Climate Change”)

As the “next few decades” are now, for us, coming to a close, where do we stand on the encouragement of energy conservation and development on alternative energy sources? Sadly the outlook is not as promising as it should be, not given our level of abilities to monitor the intricate complexities of our planet’s climate and to develop new technologies. True advancement will rely on our acceptance that a change is in fact necessary… a hurdle that is proving to be the most difficult one to clear.

Read van Oldenborgh and Haarsma’s blog post here, and see the full 1981 paper “Climate Impact of Increasing Carbon Dioxide” here. And for more news on our changing climate, visit NASA’s Global Climate Change site.

Tip of the anthropogenically-warmer hat to The Register.

March 10, 2012April 26, 2016 by Irene Antonenko

Fears of Tornado Catastrophes Due to Global Warming Unfounded

Tornadoes in the Midwest US, March 2, 2012 Tornadoes swept the Midwest US on March 2, 2012. In this image, clouds are rendered using thermal infrared (heat) and visible imagery from the Geostationary Operational Environmental Satellite-East (GOES-East). Background land information is from the Moderate Resolution Imaging Spectroradiometer (MODIS). Image credit: NOAA-NASA GOES Project/NASA Earth Observatory.

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The 2012 tornado season got off to a rousing start. Between February 28th and March 3rd, two deadly storm systems developed in the southern United States. The storms spawned numerous tornadoes that together killed at least 52 people. This kind of extreme tornado activity, so early in the year, has fueled fears that global warming will increase the severity and duration of the tornado season. But, scientific studies show that this is not necessarily to be expected.

Early tornadoes are not unheard of. For example, on February 29 in 1952, two tornadoes caused severe damage in the south-eastern US. But this year, the number of early tornadoes has been much higher. The National Oceanic and Atmospheric Administration reported that in January of 2012, the tornado total was 95, much higher than the 1991–2010 average of 35. And the five-day total for February 28 to March 3 could rank as the highest ever since record-keeping began in 1950, according to meteorologist Dr. Jeff Masters, co-founder of the Weather Underground. With such a record-breaking start, it is not surprising people worry that a more severe 2012 storm season is ahead, and that global warming is to blame.

Tornadoes form when warm and moist air from the Gulf of Mexico meets with very cold and dry air above, which was brought south from the arctic. The collision of these air masses, which have different densities, as well as speeds and directions of motion, forces them to want to switch places very rapidly. This creates updrafts of warm and wet air, which produce thunderstorms. And, as the updrafts climb through the atmosphere, they encounter fast- moving jet stream winds, which change speed and direction with altitude. These changes give the updraft a strong twisting motion that spawns tornadoes.

The severity of tornadoes is rated on the Fujita Scale, which examines how much damage is left after a tornado has passed: F0-F1 tornadoes produce minor damage and so are considered weak, F2-F3 tornadoes produce significant damage and are considered strong, and F4-F5 tornadoes produce severe damage and are considered violent. The problem with this ranking is that it is related to a human-based assessment of damage; you need something (buildings, vegetation, etc.) to be destroyed and someone to see the damage. So, a severe tornado that occurs somewhere where there is nothing to be destroyed would be classed as weak, and one that occurs where there is no-one to see the damage wouldn’t even be counted.

Still, tornado awareness and volunteer reporting programs, along with good record-keeping, have significantly improved our understanding of tornadoes and their frequency. Surprisingly, the Storm Prediction Center’s tornado database, which goes back to 1950, does not show an increasing trend in recent tornadoes. This finding is confirmed by Dr. Stanley Changnon from the University of Illinois at Urbana-Champaign, whose study of insurance industry records was published last year. Dr. Changnon’s work shows that tornado catastrophes and their losses peaked in the years between 1966 and 1973, but have shown no upward trend since that time. In fact, the number of the most damaging storms, those rated as F2 to F5 has actually decreased over the past 5 decades. So, it does not appear that global warming is increasing the number of tornadoes that occur.

This is actually not as surprising as it seems. While a local increase in temperature and humidity, whether caused by global warming or not, would be expected to create more thunderstorms, it is not clear that these thunderstorms would spawn tornadoes. The reason is that global warming does not increase temperatures the same everywhere. Warming at the poles is expected to exceed warming at more southern latitudes. This means that cold polar air will be much less colder than before and warm Gulf of Mexico air will only be slightly warmer. When these two air masses meet above the southern US, the temperature difference between them will not be so great and their drive to swap places will be much less intense. The result will be a significantly slower moving updraft of warm air that is not expected to produce as many extreme thunderstorms or spawn as many tornadoes.

So, global warming is not expected to increase the total frequency of tornado activity. However, warming global temperatures will mean an earlier spring and the potential for earlier tornadoes. In fact, the early tornado numbers we’ve seen so far this year may be a sign of a global warming-induced shift in the tornado season, according to Dr. Masters. If this is the case, the tornado season may start earlier, but it will also end earlier. As meteorologist Harold Brooks from the National Severe Storms Laboratory in Norman, Oklahoma, points out, this record start to the 2012 tornado season does not necessarily mean the rest of the season will be severe.

Sources:
Recap of deadly U.S. tornado outbreak February 28-March 3, 2012, M. Daniel, EarthSky Mar 5, 2012.
NASA Earth Observatory, March 5, 2012.
Temporal distribution of weather catastrophes in the USA, S.A. Changnon, Climatic Change 106 (2), 129-140, 2011, doi: 10.1007/s10584-010-9927-1.
Does Global Warming Influence Tornado Activity? Diffenbaugh et al., EOS 89 (53), 553-554, 2008.