When are extreme events part of natural climate variability and when are they due to climate change? It’s important to ask—no matter where you stand on the role of humanity’s impact on the environment.

A group of international scientists decided to address this question, focusing on a dozen or so extreme events from 2012. Their results were published last week in the Bulletin of the American Meteorological Society. (The findings are also available in a downloadable report.)

And the results, were, well, variable.

The researchers did not look at Hurricane Sandy, but they did examine the flooding and the inundation it caused. Because of sea-level rise (a direct result of climate change), the researchers determined that the superstorm did far greater damage than it would have with oceans at normal levels.

The team also determined that heavy rains in the United Kingdom, Japan, and China were not due to global warming, and Australia’s above-average rainfall was due to a La Niña event (or short-term climate variability).

However, a deluge in New Zealand was due to climate change. From Wired:

Total moisture available for this extreme event was 1% to 5% higher as a result of anthropogenic greenhouse gas emissions.

And Arctic sea ice melt? The cap of sea ice covering the North Pole shrunk to its smallest extent last summer. The cause? Climate change.

What about last year’s devastating drought in the Midwest? Scientists judged that climate variability was to blame—not global warming.

However, Stanford researchers did find that the extreme heat that came with last summer’s drought could be attributed to climate change. They also found strong evidence that the high levels of greenhouse gases now in the atmosphere have increased the likelihood of severe heat.

In addition, their findings indicate that extreme weather in the north-central and northeastern United States is more than four times as likely to occur than it was in the pre-industrial era.

The Palo Alto scientists hope the results from these studies can help to quantify the true cost of emissions to society, since the cost of the disaster is measurable.

“Knowing how much our emissions have changed the likelihood of this kind of severe heat event can help us to minimize the impacts of the next heat wave, and to determine the value of avoiding further changes in climate,” says lead author Noah Diffenbaugh, a Stanford associate professor of environmental Earth system science.

Image: Theresa L Wysocki/Flickr

How will climate change affect different species? Will organisms be able to adapt quickly enough to survive in a rapidly changing environment?

Researchers at the University of Oxford are attempting to predict this with small, short-lived birds like the great tit (Parus major). In a study published this week in PLoS Biology, the scientists discovered that great tits living in a forest near Oxford have been able to survive and adapt to a 1°C temperature increase over the past 50 years.

After analyzing those 50-plus years of data collected on the birds in their habitats, the authors studied when the birds lay their eggs relative to spring temperatures, as well as how the birds have tracked the shifts in peak caterpillar numbers caused by the changes in temperature. They found that the birds are now laying their eggs an average of two weeks earlier than they did 50 years ago, primarily as a result of phenotypic plasticity.

Phenotypic plasticity enables organisms to adjust their behavior rapidly in response to short-term changes in the environment. Jack Dumbacher, curator and department chair of Ornithology & Mammalogy here at the Academy, explains, “It’s heritable but it’s not an evolutionary, or genotypic change. There’s no change in the genes.”

The authors’ predictions show that phenotypic plasticity could allow the great tits—and similar birds—to survive warming of 0.5°C per year, easily outpacing the current worst-case scenario of 0.03°C from climate models.

Dumbacher says that while this study is interesting and a good reminder how adaptable one species may be, he emphasizes that temperature increase is just one effect of climate change. Temperature variance and extreme weather are other effects with unknown results to various ecosystems, he says. In addition, Dumbacher reminds us that the great tits and caterpillars play roles in a much larger ecosystem, where the web of relationships is so interdependent that one small change to one small organism in that web could easily affect other species.

One effect of climate change that Dumbacher stresses (and the study does not mention) is invasive species. As temperatures change, habitat ranges change for different species, which can result in one species invading the habitat of another. One example Dumbacher gives is the Northern Spotted Owl (Strix occidentalis caurina). These birds have been able to adapt to a 1°C temperature increase over the past 100 years but are now facing a fierce competitor in the Barred Owl (Strix varia), an eastern species that now finds itself in the same territory as the Northern Spotted Owl.

“Climate change is more than a one degree temperature increase,” Jack says. “And while a species may demonstrate plasticity within different temperature regimes, it’s likely that ecosystems are not as adaptable. This why climatologists have such a difficult time predicting the effect of climate change on organisms.”

Image: Luc Viatour/Wikipedia

Glory was to lift-off last week, but technical issues with ground support equipment for the Taurus XL launch vehicle postponed the event. NASA says those issues have been resolved and Glory is back on track!

Glory will be an important tool in understanding the Earth’s climate. One of its missions is to detect and measure the small particles in the Earth’s atmosphere called aerosols. Aerosols, or the gases that lead to their formation, can come from vehicle tailpipes and desert winds, from sea spray and fires, volcanic eruptions and factories. Even lush forests, soils or communities of plankton in the ocean can be sources of certain types of aerosols.

The ubiquitous particles drift in Earth’s atmosphere, from the stratosphere to the surface, and range in size from a few nanometers, less than the width of the smallest viruses, to several tens of micrometers, about the diameter of human hair.

The particles can directly influence climate by reflecting or absorbing the sun’s radiation. In broad terms, this means bright-colored or translucent aerosols, such as sulfates and sea salt aerosols, tend to reflect radiation back towards space and cause cooling. In contrast, darker aerosols, such as black carbon and other types of carbonaceous particles, can absorb significant amounts of light and contribute to atmospheric warming.

Aerosols are short-lived and their impacts are not fully understood. From Scientific American:

NASA climate expert and Glory science team member James Hansen has said the range of uncertainty associated with the climate impact of aerosols is three or four times that of greenhouse gases.

Glory hopes to remedy that uncertainty.

In addition, Glory will monitor variations in solar activity by measuring the amount of radiation that strikes the top of Earth’s atmosphere. The sun has been in a relatively quiet phase, even as we head to the solar maximum. The satellite could allow scientists to understand how this and future solar cycles influence climate here on Earth.

As Glory monitors the Earth’s climate, we’ll be monitoring news from the mission. Stay tuned!

“I don’t imagine you’ll ever hear the phrase ‘seal the deal’ again, unless perhaps the worst worst-case scenarios unfold and the climate system comes utterly unglued.” That’s Andrew Revkin’s reaction to the closing of the Cancun climate talks in today’s New York Times. Heads of States seemed to be missing, debates continue to rage over the Kyoto Protocol and developing nations’ and climate-affected island states’ shouts were not heard. From New Scientist:

…on the platform, the chairman of the African Union Commission, Jean Ping, noted that “Africa’s billion people are polluting roughly as much as Texas, which has 25 million people.” But Barack Obama was not there to answer.

The talks end today… don’t expect too much, says Nature’s The Great Beyond blog:

Contrary to Copenhagen, the goal going into Cancun was to make incremental progress. That seemed doable at the time, but nobody is taking anything for granted today.

Now for some fun! Through Twitter, we found this great defense of the existence of Santa… in the Multiverse. Yes, Virginia…

Follow that frog! Did you know that frogs’ bladders can hunt and remove foreign objects in their bodies? In their attempts to track frogs in Australia, scientists were implanting the amphibians with bead-sized transmitters. Within a few weeks, the transmitters had moved to their bladders and/or had simply been expelled (peed) out and left behind. Lab tests followed and results published. Read more here or here.

Bio-Inspiration: Ants travels could lead to better computer networks. According to Nature News, Argentine ants are so adept at finding the shortest routes to food and changing those routes when necessary (high traffic, obstacles), that systems engineers are hoping to learn from their behavior and build more efficient networks.

Continue to follow Science Today’s efficient science news network and lead us down some new paths by adding your comments below!

Using satellite data from NASA’s Solar Radiation and Climate Experiment (SORCE) satellite, researchers found that between 2004 and 2007, low solar activity actually resulted in more energy and visible light reaching the Earth, warming our climate. The findings are published today in the journal Nature.

Solar activity increases and decreases over a cycle that lasts roughly 11 years. Even after centuries of study, we have only begun to get a complete picture of the process. From a corresponding article in Nature:

Sunspots, dark areas of reduced surface temperature on the Sun caused by intense magnetic activity, are the best-known visible manifestation of the 11-year solar cycle. They have been regularly observed and recorded since the dawn of modern astronomy in the seventeenth century. But measurements of the wavelengths of solar radiation have until now been scant.

Instruments on the SORCE satellite measure the Sun’s energy output at many different wavelengths of light. Researchers fed the data from SORCE into an existing computer model of Earth’s atmosphere and compared their results with the results obtained using earlier, less comprehensive, data on the solar spectrum.

And the results were shocking. From New Scientist:

Previous studies have shown that Earth is normally cooler during solar minima. Yet the model suggested that more solar energy reached the planet’s surface during the period, warming it by about 0.05°C.

This surprising finding led the researchers to believe that the inverse might also be true: in periods when the Sun’s activity increases, it might tend to cool, rather than warm, Earth. But, they warn, more data are needed.

Joanna Haigh, an atmospheric physicist at Imperial College London and lead author of the study, said:

These results are challenging what we thought we knew about the Sun’s effect on our climate. However, they only show us a snapshot of the Sun’s activity and its behavior over the three years of our study could be an anomaly.

We cannot jump to any conclusions based on what we have found during this comparatively short period and we need to carry out further studies to explore the Sun’s activity, and the patterns that we have uncovered, on longer timescales. However, if further studies find the same pattern over a longer period of time, this could suggest that we may have overestimated the Sun’s role in warming the planet, rather than underestimating it.

In addition, Martin Dameris, an atmospheric scientist at the German Aerospace Center, warns that human activity still lies at the heart of our current warming trend. As quoted in the Nature article:

The findings could prove very significant when it comes to understanding, and quantifying, natural climate fluctuations. But no matter how you look at it, the Sun’s influence on current climate change is at best a small natural add-on to man-made greenhouse warming.