Scientists at the University of Helsinki this week published a paper in the journal Geophysical Research Letters, highlighting a source of emissions previously undetected. Lakes, it turns out, can be a big contributor to atmospheric carbon load. Large volumes of carbon erode off the land into lakes and once there the carbon exchanges with the air above. If carbon emissions over lakes are ignored, which they have been, an important source of the globe’s carbon budget is undetected.

The Finnish scientists took a peek above a boreal lake in their neck of the woods to see just how much carbon was seeping off into the atmosphere. They found Lake Valkea-Kotinen in southern Finland to be a net source of emissions, projecting upward of 100 grams of carbon per square meter per year. The surrounding old-growth boreal forest, on the other hand, was a net carbon sink. When considered alongside the forest, the lake’s emissions were responsible for dropping the forest’s carbon storage capacity by 10 percent.

This “natural leakage” of carbon through lakes could be worsened by climate change. Temperature and precipitation matter a great deal in how carbon gets cycled through the aquatic environment. The hotter and wetter the climate, the more carbon gets transported to the atmosphere. The UH scientists predict an increase in carbon emissions in Lake Valkea-Kotinen by as much as 26 percent by the 2050s.

Don’t forget to watch what’s happening with lakes, they say.

The U.N.’s assumption is that the world can absorb all these new people. But does the demographic forecast doesn’t square with the environmental one? Humanity long ago overshot its sustainability. And while the catastrophe envisioned by scholar Thomas Malthus has been repeatedly revived (remember dire warnings of the “Population Bomb” in the 1970s that failed to materialize?), climate change these days adds more cause for concern.

Some experts foresee a bleaker picture in which climate change and limited natural resources, like arable land and water, finally put an end to the global human growth rate.

“The growing imbalance between the increasing world population and the finite amount of Earth’s resources  that support human life is reason for grave concern,” says David Pimentel, a Cornell University professor of ecology and agriculture.

He writes that 3 billion of today’s people are malnourished, an amount he expects to grow over time as resources become more strained.

People crowd the streets of Dhaka, Bangladesh. Photo: eutrophication&hypoxia on Flickr

Most of the births these days are in developing countries, where fertility rates remain sky-high but vulnerability to the effects of climate change are heightened. Statistically speaking, the 7th billion baby is likely going to be born in the most populous state in India, Uttar Pradesh, according to children’s rights group Plan International.

Perhaps the human population will continue to grow, in spite of these constraints. But what will life look like for many of these new people? The cost of unchecked population growth is a reason to look at 7 billion quite soberly.

From politicians to everyday consumers to corporations, there seems to be a lack of incentives to act green. UK journalist John Whitfield nailed the issue on the head in the latest issue of the journal Nature Climate Change.

Whitfield, who has a book coming out next month called, People Will Talk: The Surprising Science of Reputation, says in his essay that in addition to harnessing the sun or wind for the climate’s benefit, we should also harness the power of shame.

There’s been a steady body of research showing how shame, or social reputation, can make a big mark on human behavior. The problem for the climate is that shame works best in smaller social situations where people know and trust one another. It doesn’t work so well when it comes to nations and institutions, and it almost never works when there’s no transparency of information.

Whitfield says what’s needed are more strategies to publicly reward good performers and shame bad ones. There are some good examples to go by. To increase recycling in Japan, some towns required residents to use see-through garbage bags so that a household’s waste stream could be publicly scrutinized. In the U.S., the annually updated Toxic Release Inventory has led to reductions in pollution by making public the emissions of all industrial facilities.

And for consumers, what better way to brand yourself as “green” than driving a Toyota Prius?

Green driving reaches the streets of Thailand. Photo: Ian Fuller.

Climate change is a thorny problem for shame to solve because those causing the most damage are far removed from those who will suffer the worst consequences. Wealthy Westerners emit the most carbon, but are half way around the globe from vulnerable communities and are distant in time from their great-grandchildren. Chances are they will never even see those faces.

“Reputation is built in social connections and dies at social barriers,” says Whitfield. “On climate change, the leaders of rich nations have little reputation to gain or lose by acting to aid unborn generations in distant countries.”

So what can be done?

Carbon emissions must be transparent and have some kind of public penalty. The UK has recently begun displaying plaques on public buildings showing energy efficiency ratings. Whitfield suggests rolling the program out to all homes and stores and giving prizes to the most efficient communities, “in the manner of ‘best-kept village‘ competitions throughout the UK.”

Some of this may strike Americans as too much Big Brother. But making public the data on energy use and efficiency would give public interest groups the opportunity to do something with it. Perhaps we should all know who are the energy savers and who are the energy hogs.

More than 6 percent of the sea level rise in the last century is from the movement of land-locked water to the oceans. That’s according to a new study by the U.S. Geological Survey and published in the most recent edition of the journal Geophysical Research Letters.

Groundwater depletion for human consumption and agricultural and industrial uses is known to have many negative outcomes, including land subsidence, a reduction in surface water as underground springs dry up, the depletion of wetlands, and threats to long term water supplies.

Pumping groundwater to the surface also adds to sea levels as the water is used and then discharged into sewer systems and storm drains, which ultimately empty into the oceans. How much this is happening has been a bit of a mystery because of insufficient data and previous estimates have been all over the map, says the study’s author Leonard Konikow.

Konikow set out to find the answer by developing the first comprehensive estimate of changes in groundwater storage using “volumetric accounting.” He found that from 1900-2000, the U.S. has depleted 800 km^3 of groundwater, enough to bump up sea levels by 2.2 mm. The study estimates that globally, 3,400 km^3 of groundwater has been removed from 1900-2000 during that time period, adding 9.3 mm total to the seas.

The big shocker is that the rate of groundwater depletion in the U.S. and globally steadily increased between 2000-2008. That’s resulted in a grand total of 12.6 mm to the oceans since 1900, an amount that accounts for greater than 6 percent of all sources of sea level rise.

Konikow says the results will help in assessing freshwater supplies and and create greater accuracy in the prediction of sea level rise.

The warming signal in the tropics will likely exceed past temperature ranges in the next two decades. A global temperate increase of 1 degree Celsius is lower than all economically plausible emissions scenarios. But that one degree makes a huge difference in the tropics, and is outside the natural variability in temperatures.

That’s according to a recent paper published in the journal Environmental Research Letters. Scientists at the Institute for Atmospheric and Climate Science in Zurich and NOAA Earth System Laboratory in Boulder were sifting through climate data and looking for signs of climate change on the local level. They evaluated what global temperature increase produced a “significantly different temperature regime” than early 20th century conditions.

To find new temperature regimes, the scientists had to differentiate the “noise” of local variability from the “signal” of global warming. Locations with high variability in temperatures throughout the year – namely the Arctic – are already adapted to some degree of warming in short timescales. But in the tropics, plants, insects, and reptiles may be quite vulnerable to climate change since they rarely see temperature swings, the authors of the study write.

Sadly, the most strongly affected countries also emit small amounts of CO2 per capita, meaning they have contributed little to the climate change that is now harming them.

Climate models these days have largely focused on scenarios that assume some level of restraint on greenhouse emissions, with particular emphasis on the political goal of keeping global temperatures no higher than 2 degrees above pre-industrial levels.  But scientists at the National Center for Atmospheric Research in Boulder and the Institute for Atmospheric and Climate Science in Zurich have simulated scenarios that show the upper boundaries of future greenhouse gas emissions.

In a paper published recently in the journal Environmental Research Letters, the scientists write that understanding these upper range scenarios is crucial for good decision-making about climate change.

In one climate scenario, the human population grows from 6 to 11 billion by the end of the century, while energy supplies gradually shift from today’s heavy reliance on fossil fuels to 30 percent from carbon neutral sources (compared to 14 percent in 2000). The higher demand for energy results in 55 Gigatons of carbon per year by 2100, which is similar to the highest nonintervention emissions scenarios in existing published literature. In other words, more and more people on Earth will more than erase the gains made in shifting to cleaner energy streams.

The second scenario is meant to represent a worst case situation. The population reaches 15 billion by 2100 and all the extra energy needed comes from coal, the fossil fuel with the highest amount of carbon per unit of energy. The result is emissions reaching 105 Gigatons a year.

In running the simulations, the main differences in global mean temperatures between the two scenarios doesn’t become apparent until the second half of this century. But the impacts can be seen quite starkly. Under an All-Coal scenario, 90 percent of Arctic sea ice is gone from August through October by 2060, while it takes until 2075 for sea ice to disappear in the first scenario.

From there things get steadily worse in the All-Coal scenario. Sea level increases by 8 feet over 1990 levels by 2500. Oddly enough, until the year 2100 sea levels remain nearly constant, even under no change in greenhouse gases because of the thermal inertia of the oceans.

Global temperatures shoot up to 14 degrees Fahrenheit above 1990 levels. Some parts of the planet — like the Southern Europe, Central America, and ocean subtropical regions – experience as much as an 80 percent drop in precipitation above late 20th century levels. Other regions – notably the Arctic and Antarctic – get inundated with as much as a 200 percent increase in rainfall. The Amazon basin gets hammered with a 20 percent increase in rainfall under all future scenarios.

Granted, All-Coal is the worst that can happen, and presumably (or not?) humans take action, or use up all coal reserves, before the devastation hits. But it’s a scenario worth pondering. After all, there is an influential mindset that supports using up all known coal reserves and favors unchecked population growth. This is the world they would create.

Companies in the Global 500 such as Philips Electronics, BMW, Bank of America and Sony, among others, comprise the 68 percent of respondents to the survey who say they’ve placed climate change at the heart of their business strategies. That’s a big jump above the 48 percent reported in 2010. These companies are also saying they are reducing greenhouse gas emissions.

Why are many boardrooms now getting it? The survey attributes the rising consciousness around climate change to spikes in oil prices and energy costs as well as a recognition that investments in emissions reductions pay off in as little as three years. Energy efficiency projects in buildings, for example, can easily cut company costs.

“We believe that the external costs of greenhouse gas emissions will become internalized into company cash flows and profitability,” said Steve Waygood, an asset manager at Aviva Investments in a press release.  “Managing greenhouse gas emissions is therefore essential to delivering sustainable shareholder returns.”

Some companies are setting targets in emissions reductions, and most have bumped up oversight of climate change strategies to the executive level. The biggest surprise in the report is that the companies leading the way on climate change action also had higher shareholder value with double the average of total return than others in the Global 500 over the past six years. This could be a result of more general forward-thinking management, but planning for a future world under climate change is a reality that businesses would best plan for.

There’s one business sector that’s lagging in climate action plans. Only 55 percent of energy companies set emissions reduction targets.

The discovery is just one of a number that’s expected to come out of the far-reaching expedition called HIPPO (HAIPER Pole-to-Pole Observations), which ends this week. A project of a number of federal government agencies and universities, HIPPO involved a three-year series of research flights from the Arctic to the Antarctic that measured greenhouse gases and particles in the atmosphere that affect the Earth’s climate.

The goal was to sample a broad range of molecules in the atmosphere to better understand where they are most common and how they are spreading around the world. Tracking these molecules with surface measurements, which are often separated by thousands of miles, has been “like snorkeling with a really foggy mask,” says Britton Stephens, a scientist with the National Center for Atmospheric Research (NCAR) and one of the project’s principal investigators in a press release. “Finally, HIPPO is giving us a clear view of what’s really out there,” he says.

The scientists say that the data they have gathered is “extraordinary in detail.” More than 80 gases and particles were sampled were gathered at various latitudes, during different seasons, and from different altitudes. The hope is to use the data to understand how activities like logging and regrowth of forests are affecting CO2 levels in the atmosphere. It may also provide a baseline to evaluate the success of efforts to curb CO2 emissions and the uptake and storage of greenhouse gases through natural systems.

“Carbon markets and emission offset projects are moving ahead, but we still have imperfect knowledge of where human-emitted carbon dioxide is ending up,” Stephens says.

Among the other questions that need answers: Why are methane levels increasing again, after leveling off in the 1990s?

Besides NCAR, participants included Harvard University, the National Oceanic and Atmospheric Administration (NOAA),  the Scripps Institution of Oceanography, the University of Miami and Princeton University.

Global warming is gradually unlocking these Arctic carbon reserves. In a paper published recently in the Journal of Geophysical Research, University of Alaska, Fairbanks geophysicist Guido Grosse and colleagues tease out two forces acting on the Arctic carbon reserve. “Press” disturbances present a slow, persistent force on the carbon reserves. And “pulse” disturbances present rapid and extreme releases. The result is a complicated web of environmental implications for the Arctic and the globe.

At Point Hope, Alaska, the tundra is gradually succombing to the effects of warming. Photo: Josh Kellogg.

Among the most important “press” disturbances is the continual melt of Arctic permafrost, which until now has kept deep layers of carbon-rich soil intact. By the year 2100, an estimated 20 percent of all the permafrost will be seasonal only, which has dramatic ramifications on the soil ecology. Warming soils will change the biological processes (enzyme kinetics) of plant and microbial communities, the authors write. More Nitrogen will be released, spurring plant productivity and also providing fertile ground for microbes to digest and decompose organic matter in the soil. That in turn will release carbon from the soil.

Meanwhile, with less ice cover and more coastal storms, erosion rates will increase. In the American Arctic, exposed soils from formerly covered permafrost ground are eroding at a rate sometimes exceeding 20 meters a year, resulting in substantial carbon releases into the ocean.

Pulse impacts like tundra wildfires can release massive amounts of carbon into the atmosphere, both from the soil and from vegetation. Furthermore, melting permafrost can create dramatic changes in the landscape in the form of thermokarst terrain, which when exposed can increase the thawing of permafrost.

The paper presents a dire picture of how Arctic carbon reserves may eventually be depleted.

But the picture is complicated. Farmland may not absorb much carbon, but it accumulates snow in the winter which reflects light back into space creating a cooling effect in the atmosphere. Dark-colored forests, on the other hand, absorb a lot of heat, but the vegetation also locks down carbon. So is it better to plant trees or not?

The Spessart Forest, Germany. Photo: Axel-D on Flickr.

Previous studies showed that farmland was a better mitigator of climate change in the Northern Europe than forests. But a new study out in the most recent edition of Geophysical Research Letters challenges that conclusion. Research led by Julia Pongratz at Stanford University found that you have to look more closely at the land to make a determination.

Using computer simulations, the researchers found that the most productive farmland would be better to convert back into forests, from a climate perspective. That’s because productive land can support a lot of vegetation. It would thereby capture more carbon than it would serve as a light reflector back into space when snow-covered.

It turns out, not surprisingly, that the most productive land in Northern Europe is farmland, and is also in areas with lower snowfall. The researchers conclude that, on the whole, reforesting farmland in Northern Europe would be a good thing for climate change mitigation.

They didn’t get into the economic or social aspects of taking the most productive farmland out of food production. No doubt that’s bound to raise some hackles.