Climate Compass Blog
In a recent report to the United Nations, the State Department lays out the United States’ strategy for achieving its goal of reducing emissions 17 percent below 2005 levels by 2020. The strategy is “ambitious,” as the State Department says. But a close read reveals that, in some key respects, it is more a menu of options than a clear blueprint.
The Biennial Report is the first required of parties to the U.N. Framework Convention on Climate Change as part of a series of measures aimed at ensuring greater transparency about steps countries are taking to meet their international climate pledges.
The figure below helps visualize the challenge facing the United States. The blue bar on the left represents 100 percent of U.S. emissions in 2005, or 7,195 million metric tons of carbon dioxide-equivalent emissions. On the right side is the 2020 goal to reduce emissions by 1,223 million metric tons, or 17 percent.
A quick glance around this week’s Washington Auto Show might make you wonder if you’ve stepped into the past, with large trucks, SUVs, and sports cars getting all the attention. But look under the hood and you can see the auto industry’s more climate-friendly future.
The cars and trucks of 2014 are lighter, more aerodynamic, and powered by increasingly efficient engines. A key impetus for these improvements is tougher federal fuel economy and greenhouse gas emission standards. The auto show provides evidence that the industry is working to meet these ambitious standards, and that we can significantly reduce emissions without compromising consumer choice.
One way to improve fuel economy is to make the vehicle lighter. That’s exactly what Ford Motor Company did to the best-selling vehicle in the United States: the F-150. All 2015 Ford F-150s will have an aluminum body and truck bed – shedding 700 pounds while still being able to tow and haul more than the previous generation. That could boost its gas mileage from 20 mpg on the highway for the 2014 model to 30 mpg.
Automakers have increasingly substituted strong, lightweight aluminum for steel in hoods, wheels and other components. The F-150 and Tesla’s aluminum-body Model S show they’re going beyond that.
Another way to increase gas mileage is to improve an engine’s ability to convert fuel (potential energy) to work (kinetic energy). General Motors is making the Corvette Sting Ray for the first time 1976, and the new version is beautiful and efficient. The 2015 Sting Ray is the quickest, most powerful, and most efficient Corvette ever made. The 7-speed V-8 Sting Ray gets up to 29 mpg on the highway. That’s about twice the fuel economy of the ’67 Sting Ray my dad drove when I was a kid.
President Barack Obama used his State of the Union address to remind Americans and Congress of the importance of protecting both our environment and our economy by addressing climate change.
As I wrote on the National Journal Energy Insiders blog, the president made three key statements that are worth repeating and exploring:
As President Barack Obama prepares to deliver his State of the Union address, we believe it’s a good time to take a look at the state of our climate: the growing impacts of climate change, recent progress in reducing U.S. emissions, and further steps we can take to protect the climate and ourselves.
The consequences of rising emissions are serious. The U.S. average temperature has increased by about 1.5°F since 1895 with 80 percent of this increase occurring since 1980, according to the draft National Climate Assessment. Greenhouse gases could raise temperatures 2° to 4°F in most areas of the United States over the next few decades, bringing significant changes to local climates and ecosystems.
This week’s brief but bitter cold snap over more than half the country prompted intense discussion about the polar vortex ranging from educational to bombastic.
|Figure 1: A depiction of the “average” polar vortex on Jan. 6. The winds of the vortex correspond to the narrow “rainbow” areas. The map is an average of the upper atmosphere’s “topography” (specifically, the 500 millibar height) from all the January 6ths between 1980 and 2010.|
|Figure 2: The polar vortex on Jan. 6, 2014. The ridge (“R”) and trough (“T”) responsible for relatively warm weather in much of the West and bitterly cold weather in the Midwest and East have been labeled.|
So let’s be clear: The cold snap this week was unusual but not entirely unprecedented. A few super-cold days don’t disprove global warming, just like a day of rain doesn’t end a drought. At the same time, we don’t yet know whether climate change will change the odds of future outbreaks of bitter cold. Research is still underway, and as of now, we shouldn’t necessarily expect these events to be more or less frequent in future winters.
Here’s a Q&A to cut through the hype:
- What is the polar vortex? The polar vortex describes the air circulating aloft (thousands of feet above the ground) about the North Pole, and its extent is marked by a ribbon of strong winds that is often called the “jet stream.” (We most commonly focus on the North Pole, but a similar circulation is present around the South Pole, too).
In the map (Figure 1), which is from the point of view of the North Pole, the vortex corresponds to purple and blue colored areas. The band where the colors change from blue/purple to red/yellow indicates the location of the jet stream, or the outer edge of the vortex. Winds are strongest where this color gradient is tightly packed (e.g., over the Pacific Ocean and North Atlantic Ocean). It tends to be quite cold at the surface below the purple areas, and warmer under the red/yellow areas.
It’s important to note that this figure is an average of many winter days. On any given day, we would see a number of deviations from this average pattern.
- What happened this week? Comparing this week (Figure 2) to the average picture (Figure 1), we can see that the purple area of the vortex has contorted and moved farther south. Along with this pattern, there are substantial “wiggles” in the jet stream. These deviations in the circulation helped bring cold air into the continental United States that normally stays in northern Canada and the Arctic. Meteorologists look for these wiggles, called “ridges” and “troughs” (“R” and “T” on the map) when putting together a forecast. While the trough brought notable cold to the Midwest and the East, the ridge has kept parts of the West warmer than average and relatively dry (much to the dismay of skiers).