Happy Earth Day! We would like to share a few recent headlines for you to peruse to ponder and protect our planet…

Pollution
From high to low, all around the world, pollution affects our world. Recent headlines show that “Toxic chemicals are accumulating in the ecosystems of the Himalayas and the Tibetan plateau,” according to Nature. Tiny plastic particles aren’t just trouble in the oceans; the Great Lakes contain millions of microplastics, too. The New York Times’ Dot Earth blog has a short post about the importance of not littering. And National Geographic has an article about how pollution on land can affect marine life like dolphins and local sea otters.

Colorado River
While many U.S. rivers have problems with pollution, the Colorado River’s mismanagement, overuse and drought put it atop the list of Endangered Rivers of 2013. National Geographic has an entire series on the Colorado River delta, and the New York Times has offered both an article and video last week on the region’s hopeful revival.

Drought
Speaking of drought… Do drought-stressed trees cry for help? French scientists are listening for clues. Climate change was not responsible for last summer’s Midwestern drought, according to NOAA, but then what was? And how might we be able to predict future droughts?

Climate Change
Climate change may not have caused of the recent drought, but it is responsible for other devastating events and looming disasters: bumpier flights, more storms, bark beetle plagues, drowned islands, failures in agriculture systems and more extinctions. Researchers are also getting a better handle on tracking climate change through mapping ocean eddies and looking at historic ocean temperatures and air pressure.

Ecology
How do species react to environmental changes? Rapid evolution, according to one study. Another study suggests that endangered species are already doomed. And Nature offers an update on a decades-long study of habitat fragmentation in the Amazon.

Energy
How has energy usage in our country changed over the past two hundred years? NPR has a graph (or four) for that. In response, Scientific American presents a diagram illustrating our potential for future alternative energy use and resources accompanying an article titled, “How to Power the World without Fossil Fuels.” Germany seems to have taken notice—the European country has ambitious renewable plans. But it’s not the only one. The U.S. had a huge year in 2012 for wind power. And, heading across the country soon? How about a solar-powered flight?

Earth Day
Finally, let’s truly celebrate the planet’s holiday with history, maps, jokes about Earth Day, and facts and photos of our beautiful home.

Image: Terra/ASTER/NASA and NASA Earth Observatory

Each fall, monarch butterflies east of the Rockies make the long migration to their overwintering site in Mexico. Scientists have exposed the internal rhythms that tell the butterflies where to go, despite the fact that the site was last visited by their great-grandparents. But how do the butterflies know when it’s time to leave Mexico and head north again?

Researchers at the University of Massachusetts suspected that temperature or daylight had something to do with it, so they collected wild monarchs at the start of their southward fall migration, brought them into the lab, and divided them into three groups. Two of the groups were exposed to the same cooler temperatures they would experience in their overwintering ground in Mexico. In addition, one of these two was also exposed to the same changing light levels they would experience south of the border. For the third group, the temperature remained warm and light levels never changed.

When placed into a flight simulator 24 days later, the first two groups of monarchs began flying northward. The third group, not exposed to cooler temperatures, continued flying southward.

If temperature alone determines when the butterflies start their northward migration, scientists raise concerns about the effects climate change will have on these beauties. “Without this thermal stimulus, the annual migration cycle would be broken, and we could lose one of the most intriguing biological phenomena in the world,” says Steven Reppert. His study, coauthored with Patrick Guerra, appeared last month in Current Biology.

Sadly, on the heels of that study comes a report issued last week on the decline of monarch numbers in Mexico this past winter. The study blames drought in the American southwest and an increase in soy and corn farming. Both are responsible for a loss in the milkweed plants the butterflies rely on for food during their long migrations.

“If people want to help,” says Craig Wilson of Texas A&M University, “they can pick up some milkweed plants right now at local farmer’s cooperative stores and this would no doubt be a big boost to help in their migration journey. It is important to have a national priority of planting milkweed to assure there will be monarchs in the future. If we could get several states to collaborate, we might be able to provide a ‘feeding’ corridor right up to Canada for the monarchs.”

Image: Kenneth Dwain Harrelson/Wikipedia

Four amazing and passionate scientists discussed different aspects of our changing world—wildlife, drought, storms and the tree-ring record—at a press conference titled, “Did Climate Change Cause Superstorm Sandy?”

Remember, these are scientists, not politicians (see more in Andy Revkin’s New York Times blog). They need evidence to see causal effect between one event and another. And for these recent storms and weather patterns, there just isn’t enough evidence. Yet.

But are these researchers glad that these events are focusing Americans’ attention (including the President in his recent State of the Union address) on climate change? Most definitely. Yes.

Here’s what they do know. Climate change is affecting the probability of storms like Sandy and Nemo. There is evidence that in our warming world, severe storms will happen more frequently.

Researchers understand that global warming and other human-related activities are affecting where animals live, move and mate, and when plants bloom.

Scientists also know that temperature increase is one factor in drought. Texas temperatures have risen steeply in just the past 15 years and drought has increased.  And now Texans are talking about climate change, said John Nielsen-Gammon of Texas A&M University. The drought alone didn’t alarm them about climate change, but the decreased water supply has made people and politicians alike take notice.

And the speakers are hopeful and passionate that we’ll start doing something about these effects—reducing fuel emissions, restoring habitats, becoming more aware of climate change.

What do you know and feel? Share with us here.

Midwest drought image: cwwycoff1/Wikipedia

Yesterday, James Hansen of NASA’s Goddard Institute and Thomas Karl of NOAA’s National Climatic Data Center held a joint press conference, describing very similar findings for last year’s warmer than average temperatures around the world. A pdf with their organizations’ side-by-side comparisons is available here.

The average temperature globally in 2012 was about 58.3 degrees Fahrenheit, which is 1.0 F (0.6 C) warmer than the mid-20th century baseline. The average global temperature has increased about 1.4 degrees F (0.8 C) since 1880, according to the new analysis.

The scientists emphasized that weather patterns always will cause fluctuations in average temperature from year to year, but the continued increase in greenhouse gas levels in Earth’s atmosphere assures a long-term rise in global temperatures. Each successive year will not necessarily be warmer than the year before, but on the current course of greenhouse gas increases, scientists expect each successive decade to be warmer than the previous decade.

“The U.S. temperatures in the summer of 2012 are an example of a new trend of outlying seasonal extremes that are warmer than the hottest seasonal temperatures of the mid-20th century,” Hansen said. “The climate dice are now loaded. Some seasons still will be cooler than the long-term average, but the perceptive person should notice that the frequency of unusually warm extremes is increasing. It is the extremes that have the most impact on people and other life on the planet.”

In fact, according to Reuters, Americans are feeling the impact of climate change already—consequences that affect “health, infrastructure, water supply, agriculture and especially more frequent severe weather.”

But studies show we can do something about it. Nature Climate Change has an article this week describing how cutting emissions can reduce impacts from climate change. (Read more at Scientific American.) And New Scientist reports that while global talks breakdown over the subject, individual nations are doing something about it. Let’s hope the trend continues.

Want to engage more in the changing climate? Tomorrow Science will host a live chat, “Can We Conquer Climate Change?” Sign in here.

Image: NASA Goddard’s Scientific Visualization Studio

Another climate and water story

Last week, we featured a series of stories on climate change and water issues and this one slipped by. A study in Nature last week reported how trees physically respond to drought. And the news is not good. Plants undergoing drought stress experience reduced pressure in the xylem (the vessel that transports water from the soil to the leaves).

Head over to NPR to read (or listen to) their piece on the study.

Melting ice sheets and sea level rise

A NASA/ESA study, published in Science this week provides the most thorough representation of the rate of melting ice sheets and corresponding sea level rise to date. Using extensive satellite data, scientists report that the ice sheets covering Greenland and Antarctica are losing more than three times as much ice each year as they were in the 1990s. About two-thirds of the loss occurs from Greenland, with the rest from Antarctica.

Combined, melting of these ice sheets contributed 0.44 inches to global sea levels since 1992. This accounts for one-fifth of all sea level rise over the 20-year survey period. The remainder is caused by the thermal expansion of the warming ocean, melting of mountain glaciers and small Arctic ice caps, and groundwater mining.

“Both ice sheets appear to be losing more ice now than 20 years ago, but the pace of ice loss from Greenland is extraordinary, with nearly a five-fold increase since the mid-1990s,” NASA’s Erik Ivins says.

Ocean acidification and fighting back

Ocean acidification is already having an effect on marine life, according to a study published this week in Nature Geoscience. Shells of live mollusks from the Southern Ocean are showing signs of “severe dissolution.” New Scientist has more information.

Washington State is taking action to curb ocean acidification and protect the state’s large shellfish industry. A report, released this week, outlines plans to target pollution that causes acidification (including carbon emissions and agriculture run-off) and has a $3.3 million backing. More information is available here.

Maybe more coastal states (and nations) will follow Washington’s lead, says the Ocean Conservancy.

A Sad Factoid

A final thought from the editors at grist.org, who note that “if you’re 27 or younger, you’ve never experienced a colder-than-average month.” A truly sobering fact gleaned from the NOAA “State of the Climate” report for October 2012.

Image: Ian Joughin

Since the mid-1960s, the Palmer Drought Severity Index (PDSI) has been the standard of measuring drought, reviewing temperature and rainfall information over a period of time. But a recent study in Nature states that the measurement may be too simple.

The PDSI looks at potential moisture evaporation from the soil in terms of temperature and plant use. But researchers at Princeton University see other clues to evaporation—wind speed, humidity and solar radiation—that could contribute to the evaporation and drought estimation.

The Intergovernmental Panel on Climate Change (IPCC) uses the PDSI to assess drought. In their 2007 report, they noted that droughts have intensified since the 1970s. But the Princeton team finds that there has been little change in droughts over the past 60 years. According to Science Now,

… the new assessment technique found that between 1980 and 2008, the global area stricken by drought grew by approximately 0.08% per year—less than one-seventh the increase estimated by the temperature-only version of PDSI…

The results of the study have implications for how we interpret the role of global warming on changes to the weather and its extremes like drought. The authors stress that this finding does not rule out drought as a response to future climate change. It just gives scientists a better way to measure and predict drought.

Tomorrow: Sustainable groundwater

This week, we’ll look at recent research on water and climate. Today we’ll start in the past, to understand how climate and water affected human life hundreds of years ago.

The collapse of the Maya is one of the world’s most enduring mysteries. But a recent study in the journal Science, combining a precise climatic record of the Maya environment with a precise record of Maya political history, may provide a better understanding of the role weather had in the civilization’s rise and fall.

And it all has to do with water—plentiful rainfall, followed by drought. The researchers studied the isotopes in 2,000 year-old stalagmite samples from a cave in Belize. Nature News describes the process:

The team estimated historical rainfall in the Mayan lowlands by measuring oxygen isotopes incorporated into the stalagmite from rainwater that seeped into the cave from the ground above. The precipitation levels were tied to specific dates by measuring the ratio of radioactive isotopes in the stalagmite.

“Unusually high amounts of rainfall favored an increase in food production and an explosion in the population between AD 450 and 660,” says Douglas Kennett, lead author and professor of anthropology at Penn State. This high amount of rainfall, he says, was followed “by a series of major droughts that triggered a decline in agricultural productivity and contributed to societal fragmentation and political collapse. The most severe drought (AD 1020 and 1100) in the record occurs after the widespread collapse of Maya state centers and may be associated with widespread population decline in the region.”

Social unrest is often tied to drought and food availability. If drought should persist because of global warming in the future, perhaps we can learn from the Maya, says co-author Bruce Winterhalder, of UC Davis. “It’s a cautionary tale about how fragile our political structure might be. Are we in danger the same way the Classic Maya were in danger? I don’t know.”

Tomorrow: Are droughts overestimated?

Image: Douglas Kennett, Penn State

Despite the important role of understory plants in forest ecosystems, climate impact assessments on understory plants and their role in supporting wildlife habitat are scarce in the literature.

That’s part of an abstract in a new paper in Nature Climate Change. A group of researchers at Michigan State University and the Chinese Academy of Sciences decided to look at the future of a few bamboo species under different climate change models.

The scientists studied bamboo species that carpet the forest floors of prime panda habitat in northwestern China. Unlike some of the more common, fast growing-species, the bamboo species that serve as understory in the Qinling Mountains only flower and reproduce every 30 to 35 years, which limits the plants’ ability to adapt to changing climate and can spell disaster for a food supply and more.

These mountains are home to about 275 wild pandas, or 17 percent of the remaining wild population. Bamboo makes up 99% of the giant pandas’ diet. Sadly, even under the most optimistic climate change scenario, bamboo die-offs would effectively cause this prime panda habitat to become inhospitable by the end of the 21st century.

The scientists are aware of how important the pandas are in telling this story. “The giant panda is a special species,” says lead researcher Mao-Ning Tuanmu. “People put a lot of conservation resources into them compared with other species. We want to provide data to guide that wisely.”

But the pandas are only a part of the story. Bamboo is a vital part of forest ecosystems—providing essential food and shelter for other wildlife, including other endangered species like the ploughshare tortoise and purple-winged ground-dove. It’s all interconnected. From Science News:

Scientists need to pay more attention, the team writes, to how changes in one part of the ecosystem (like bamboo) affect others within the same ecosystem (like pandas).

Image: MSU

For scientists, policy-makers and organizers who frequently discuss climate change, the last few years have been rough! While they still may be discussing it amongst themselves, with the economic downturn, a larger audience has been absent. An episode of Frontline explores the massive shift in public opinion on climate change.

But the last two weeks might change all of that.

Hurricane Sandy affected so many people that climate change popped up in many new conversations. Click on these questions to find some of these headlines:

• Was the storm caused by climate change?
• Are humans to blame?
• Will global warming bring more “frankenstorms” like Sandy?
• How can cities protect themselves?
• What are some of the financial impacts?
• How can communities adapt to a new normal of storms like these?
• How do we find stormproof solutions?

Will Obama’s second term allow him to speak more freely (and more urgently) about climate change? Scientific American says that we’ll likely only see “more of the same.” But New Scientist has some suggestions about how he can create a “climate change legacy.” And Brandon Keim, in Wired, sees opportunity for the President:

A cap-and-trade system for carbon pollution is unlikely, but other approaches are possible, from adapting infrastructure and improving post-disaster resilience to revenue-neutral carbon taxes and reduced fossil fuel subsidies.

Let’s hope these conversations start quickly (the Academy’s Peter Roopnarine blogs about climate change, providing many conversation starters). According to recent news headlines (here and here), we’re quickly looking at worst-case scenarios for global warming.

What do you want to say about climate change? Share below.

Image: NOAA