A collection of climate change headlines from this month…

Earlier this month our planet hit a milestone number: 400 parts per million. That’s the amount of carbon dioxide in our atmosphere. From the Elements blog in the New Yorker:

…the number should shake us, if not shock us. We’ve got more carbon dioxide in the atmosphere now than at any point since the Pliocene, when there were jungles in northern Canada.

What this means for life on Earth is measured, modeled and forecasted by scientists every day. But there’s no doubt that the rise in CO2 is causing global warming. Long gone is the argument that scientists disagree on the matter. A paper published two weeks ago in Environmental Research Letters, determines once again that 97% of researchers agree that current climate change is human-caused.

Melting Ice and Rising Seas

We’ve mentioned the effect of melting Arctic sea ice to sea level rise around the world. A study this month demonstrates that continental glaciers (such as the Greenland one, pictured above) will do even more damage. In fact, another study notes that as glaciers melt in Greenland, the locations of Earth’s poles are changing.

Plants and Animals Feel the Effects

Other recent studies examine the effect of climate change on plants and animals around the globe. Traditional wine-growing locations could be too warm to support vines in the near future. Living in the Arctic, polar bears’ immune systems aren’t as robust as organisms living in warmer climes. With the region warming, researchers are concerned that the iconic white bears could be more vulnerable to disease. Another recent paper reveals that fish and other ocean life are moving toward the poles to escape warming seas. Finally, another paper this month explains (once again) that more than half of common plants and one third of animals could see a dramatic decline this century due to climate change.

Extreme Weather

Can we use Australia as a model of the extreme weather we may see as global warming continues? Time will tell. But even though scientists determined that climate change wasn’t a factor for the recent devastating tornado that hit Oklahoma, scientists believe that future tornados could be more damaging thanks to a warming Earth. Deaths due to heat waves in New York will also increase with climate change, according to a paper last week in Nature Climate Change.

Warming Slowdown?

Another paper last week purports that the world is warming slower than expected and that perhaps we will have a second chance. Will we use the time wisely and reduce our CO2 emissions? What do you think?

Image: Michael Studinger/NASA

Groundwater

Groundwater was the subject of three studies and several articles in May. Two of the studies look at the effect of pumped groundwater on sea level rise, and both papers agree that groundwater has had a significant impact on global sea level rise. Nature News has details from both the Nature Geoscience study and the Geophysical Research Letters study. Science News does, too, and gives the details in context:

In recent years, sea level has been rising around 3.1 millimeters each year. Besides groundwater depletion, other major contributors include the melting of glaciers and polar ice fields, and the expansion of ocean water as it heats up.

Over at National Geographic Newswatch, Sandra Postel laments the out-of-sight, out-of-mind nature of groundwater. She gives her most endangered aquifer list and includes a video to raise awareness about groundwater depletion.

A study this week in the Proceedings of the National Academy of Sciences highlights the increase in groundwater use in California and Texas. The study’s authors used water level records from thousands of wells, data from NASA’s GRACE satellites, and computer models to study groundwater depletion in the two regions. GRACE satellites monitor changes in Earth’s gravity field that are controlled primarily by variations in water storage.

Irrigation for agriculture is the main cause of groundwater depletion, and the researchers urge more efficient and sustainable irrigation practices before it’s too late.

So little water…

Did you see this fabulous illustration (above, right) of all the world’s water? It was distributed by USGS in mid-May. Please read the fascinating description at their site.

Earlier this week, the Academy and its partners in the Worldviews Network released a short Google Earth based film on global water issues. Like the USGS illustration, it gives perspective of Earth’s available water. It also plunges users into water issues relevant at global and regional scales—especially relevant to the dry American Southwest. You can also play around with the liquid data on your own, using Google Earth.

Local drinking holes

UC Berkeley researchers have developed floating robots to work with smart phones and monitor water flow, especially in river systems like the all-important Sacramento-San Joaquin River Delta. Scientists hope that having a high volume of sensors moving through the water can shed light on processes influenced by water movement, such as the spread of pollutants, the migration of salmon, or the mixing of salt and fresh water in the Delta’s ecosystem. More information is available here.

Thirsty for more?

Scientific American has an in-depth report on the freshwater crisis—including an interesting infographic on water usage by country. Nature News describes a Canadian “laboratory” of lakes on the verge of closure. And an upcoming experiment in the Grand Canyon will see if more water will restore ecosystems for native fish, the New York Times reports.

Image: USGS