Author: Scott K. Johnson

(credit: NASA/GISS)

After 2014 set the record for annual average global surface temperature, 2015 promptly smashed it. By the end of 2015, the incredibly strong El Niño that had developed to help fuel that record enabled climate scientists to predict that 2016 was almost certain to break the record again. With the first half of 2016’s temperatures in the books, this prediction is proving to be on target.

In a press conference Tuesday, NASA scientists highlighted the standout temperatures we've seen so far in 2016. This has been, far and away, the warmest January-to-June period on record.

Even though the El Niño event has now come to an end, with forecasts pointing to cooler La Niña waters in the eastern equatorial Pacific Ocean, 2016 is a virtual lock to be significantly warmer than 2015. This June also set the record for the warmest temperature on record in June—the 8th straight month that this has happened.

Texas Congressman Lamar Smith has had an eventful run as chair of the House Committee on Science, Space, and Technology so far. And his most colorful highlights revolve around climate science. Smith, who rejects the central conclusions of climate scientists, has been demanding the e-mails of NOAA scientists, whom he has accused of manipulating data for a 2015 study published in the journal Science, even though that work is publicly available, independently replicated, and scientifically uncontroversial.

Recently, he has turned his focus to several state attorneys general who are pursuing investigations of Exxon Mobil. Some recent media reports revealed that Exxon’s own climate research in the 1970s and '80s concluded that climate change was human-caused. But the company later reversed course and campaigned to block any climate policies. Several investigations are now looking at whether, in doing so, Exxon mislead its shareholders. The investigations are modeled after the cases brought against tobacco companies in the 1990s.

In May, Smith subpoenaed 17 attorneys general and 8 environmental groups for any communications related to these investigations, describing them as “a coordinated attempt to attack the First Amendment rights of American citizens”.

If the CSI family of television shows has blunted your appetite for impossibly omniscient crime scene analysis, consider the real, and very serious, science of nuclear forensics. If someone flouts the ban on nuclear weapons testing, we want to know as much about it as possible. And the resources backing that effort are substantial.

Seismic waves betray the occurrence of underground tests, and air samples grabbed soon afterward can contain the radioactive proof. But both are transient, and even radioactivity at the site of the explosion can fade too quickly to be of much use. A group of researchers at Los Alamos National Laboratory have demonstrated a new technique than can reveal the potency of the bomb from the debris—even decades after the fact.

To test the technique, they tried it out on the famous 1945 Trinity test site in New Mexico, where the very first atomic bomb was detonated less than a month before nuclear bombs were dropped on Hiroshima and Nagasaki. The heat of the blast fused the sandy surface into glassy rock that took on the name “trinitite.” Immediately after the explosion, that trinitite would have been loaded with short-lived radioactive isotopes that could tell you about how the bomb functioned, but the most important indicators dissipate within months.

While sea ice in the Arctic has shrunk remarkably over the past few decades, sea ice around Antarctica has been dancing to the beat of a different drum. You might expect that as the world warms, sea ice would dwindle no matter which end of the planet it’s on, but the two regions are quite different.

While the North Pole sits in an ocean surrounded by land, the South Pole is in a continent surrounded by water. Antarctic sea ice grows outward from the coast, aided by the isolating winds that encircle the continent and carry frigid, inland air that pushes the ice around. So even as warmer water reaches under the floating ice shelves of Antarctica’s glaciers, persistently eating away at them, the growth of winter sea ice is more closely tied to wind patterns.

Climate models project a big decline in Arctic sea ice, with the end of summer becoming essentially sea-ice-free within a few decades at the current rate of warming. But in Antarctica, the models project smaller long-term declines.

Few environmental limits are as obvious to people today as water availability. Particularly in drier climates, availability can be a pretty unforgiving equation. Even there, a family might pay less for water than for cell phones, but there is often a pretty complex system behind your tap that keeps it running.

The challenge of water availability rises beyond engineering. It becomes a delicate dance managing demand, forecasting supply, and sustaining ecosystems. Decisions have to be made based on information that is never complete, so any opportunity to obtain more useful information is liable to get a thirsty look from water managers.

Of course, a truck load of information won’t do you any good if you can’t extract the bits you need. One tool for working with potentially valuable truck loads is an artificial neural network—a software system that uses machine learning techniques to process tons of data and intelligently answer questions. And one company is now applying IBM’s Watson machine learning system in an interesting way to tell water utilities something they would love to know: how efficiently their customers are using water.

If anyone thought that December’s historic Paris climate agreement meant the problem of climate change was officially solved, they got the wrong idea. While a critical first step, the emissions cuts pledged cannot be the end of the story if we want to stabilize our unintentional experiment with Earth’s climate.

Technically, the 195 countries in on the pact are agreeing to keep global average temperatures less than 2°C above pre-industrial times. In fact, a late addition to the agreement purports to aim to stay below 1.5°C above. Unfortunately, it now seems that the actual emissions pledges submitted by each nation (which go through 2030) don’t get us there.

A team led by Joeri Rogelj of Austria’s International Institute for Applied Systems Analysis has published a close look at those pledges to show us just where we’re at. They compare several scenarios for future greenhouse gas emissions: a baseline “no policy” world in which no cuts are made, a world in which only existing (pre-Paris) policies are in effect, a Paris Agreement scenario, and a more aggressive scenario that would obey the 2°C limit.

In the immediate wake of a weather disaster, people like to wonder whether climate change is partly to blame for the disaster's severity. The problem is that any meaningful, serious answer to that question takes time—so much time that public attention has moved on before we get an answer.

For one group of climate scientists, that unfortunate problem sounded more like a challenge. With a good plan and the right setup, the team figured it could quickly run the necessary climate model simulations and spit out some basic results. By comparing a virtual world where humans didn’t drive up concentrations of greenhouse gases to the one we live in, the models can be used to see whether there's any change in the weather patterns associated with the latest disaster.

At the end of May, the team got a chance to take its system for a test drive. Weather linked to a lingering low pressure system dumped rain on France and Germany. Three days of steadily heavy rain, following a wet spring, caused flooding on the Seine and Loing rivers upstream of Paris. In Paris, the water level in the Seine rose more than 6 meters (over 20 feet), prompting the evacuation of art from basement levels of the Louvre. In other areas, thousands of human beings were evacuated as well.

Plastics are great. They can take any shape and serve an endless variety of roles. But... the beginning and end of a plastic’s life are problematic. While some plastics are made from renewable agricultural products, most are derived from petroleum. Plastics are not as easy to recycle as we'd like, and a huge percentage ends up in landfills (or the ocean), where they can be virtually immortal.

The easy way to recycle plastic is to just rip it up, melt it down, and pour a new mold. But that only works when the plastic is all the same chemical type, which is a level of purity you rarely find in a recycling bin. Without separating plastics precisely into different types, you get a mixture that is much less useful than pure plastics. We’re limited in what we can make out of it. Other methods for recycling plastics require serious energy input, like high pressure and temperatures over 400°C. That can produce a variety of hydrocarbon compounds, but they can be difficult to work with.

Recently, a team led by Xiangqing Jia of the Shanghai Institute of Organic Chemistry decided to try some chemical tricks to turn some of these plastics into something useful, even if it’s not more plastic. They worked with polyethylene, which makes up the majority of the plastic we use. Polyethylenes are essentially long chains made of repeating links of carbon, with hydrogen hanging off the side. The challenge is to break that resilient chain into shorter pieces so we can use the pieces to make other compounds.

As the world continues its slow shift to renewable energy, it would be great to limit the carbon dioxide produced from the fossil fuels we'll burn in the meantime. Some researchers are working on capturing that CO₂ from smokestacks using as little energy as possible. Others are working on places to put it.

Deep, briny aquifers are an obvious choice. The concern there is the risk of leakage. Once we put the CO₂ deep into the Earth, we want it to stay there. Eventually, the CO₂ dissolved in those brines can precipitate as carbonate minerals (which won't be going anywhere), but that takes a pretty long time.

Brines aren't the only option for locking away captured CO₂, though. There are also volcanic rocks that will readily react with CO₂, potentially speeding things along. In 2012, a pilot project got rolling in Iceland to inject CO₂ into basalt—something the island nation has in abundance. An impressive outcome from this pilot is reported in a new paper published in Science.

One of the undying, zombie-like arguments against climate change is that you can’t trust climate scientists because they started out making doom and gloom claims about global cooling in the 1970s. But this, along with many other things comedian Dennis Miller has said on late night talk shows, needn’t be taken seriously.

By the time fears of an ice age reached the public's attention, there was a long history of concerns about warming. The idea that burning fossil fuels would warm the planet can be traced back to an 1896 paper by Swedish scientist Svante Arrhenius. In the 1930s, Britain’s Guy Callendar concluded that global warming was already underway. So it seems a bit odd that anyone worried about cooling. What was really going on back in the 70s—both in science and in the media?

Reaching maturity

For climate science, the 1970s were a pivotal era. Even though the discipline was born much earlier, it’s probably fair to say that climate science grew up in that decade.