Climate Compass Blog

A new twist in the global warming hiatus

The Earth is undoubtedly warming, hitting a high mark just last year. Fourteen of the 15 hottest years since we started keeping records over 100 years ago have happened since 2000.

Taking the Earth’s Temperature

Measuring temperature may seem like a straight-forward task. But taking the temperature of the entire planet can be complicated. People are only living on a small portion of the Earth’s surface. Moreover, it is challenging to put together old and new records from many different instruments and methods. Here are some examples of challenges that exist in combining temperature records:

Buoys vs. ships: Buoys are programmed to measure temperature at specific intervals. Ship-based measurements are less regulated and are often taken voluntarily, at the convenience of the crew. It can be difficult to compare data if measurements are not synchronized.

Measurement techniques on ships: A small but significant percentage of ship-based measurements are still taken using buckets dipped into the ocean, in contrast to the widely-practiced method of using thermometers mounted under the water at engine cooling intakes. The bucket method can introduce multiple biases - human error, evaporation rates, bucket material and condition - that are not present with underwater ship-based and buoy measurements.

Getting sufficient coverage: People and technology are not evenly distributed around the planet. Due to a lack of spatial uniformity, temperature data in polar regions – locations warming faster than the rest of the planet – is sparse. However, as new sensors are installed in increasingly remote locations and more robust data sets are developed, scientists can access more information about the Earth’s surface to better estimate the global temperature.

But was there a slowdown in the rate of warming in the last 15-20 years, a “hiatus”?

Researchers at the National Oceanic and Atmospheric Administration (NOAA) say no.

Earlier research appeared to show that the rate of warming from 1998 to 2012 was less than half the rate of previous decades, prompting some to say global warming had “paused.” Looking at the newest data, however, NOAA researchers have concluded that the perception of a hiatus is “no longer valid.” In other words, they argue that recent warming has been larger than previously reported.

What is new about NOAA’s analysis?

The NOAA team updated estimates of the planet’s surface temperature in four ways:

  • Reconciling differences between ocean temperature measurements made by buoys, which are more recent and appear to be higher quality, and by ships, which constitute most of our ocean temperature readings in the early part of the 20th century.
  • Reconciling differences between ocean temperature readings made using water in ships’ engine intakes versus those made using buckets (see Box).  
  • Incorporating recently released ground-based temperature measurements, which include better coverage, especially in the Arctic.
  • Adding data from 2013 and 2014. These years were some of the warmest on record, and including them boosts the recent warming trend.

Following these corrections, the rate of warming during 1950-1999 (0.113°C/decade) is virtually identical to the rate of warming during 2000-2014(0.116°C/decade).

Looking back at the full observation record (1880-present), the rate of warming with these corrections factored in is essentially the same as in NOAA’s   previous analysis (0.068°C/decade and 0.065°C/decade, respectively). As stated by the NOAA team, “this reinforces the point that corrections mainly have an impact in recent decades.”

Kudos to bipartisan ideas for the Clean Power Plan

Debate over the proposed Clean Power Plan has been, not surprisingly, contentious and, unfortunately, partisan. On one end, some Republicans are promoting a just-say-no approach, discouraging states from developing plans to cut carbon emissions from their power plants, as the proposed rule would require. On the other end, some Democrats are refusing to acknowledge the genuine challenges the proposal presents to states and the power sector.

With all the partisan rancor surrounding the plan, it was refreshing to see a bipartisan group of senators take a different approach. Senators Lamar Alexander (R-TN), Cory Booker (D-NJ), and Tom Carper (D-DE) came together last week to offer constructive comments on the proposal in a letter to Environmental Protection Agency (EPA) Administrator Gina McCarthy.

Smarter homes: comfortable, convenient and climate-friendly

States could go a long way toward meeting targets for reduced power plant emissions under the Clean Power Plan just by encouraging energy efficiency. One way to do that is to deploy more “intelligent efficiency” solutions at home. Interconnected systems and smart devices could not only help reduce energy use and climate-altering emissions, but also empower consumers to make money-saving choices.

More than 20 percent of U.S. greenhouse gases comes from the residential sector – where we use about 1.4 trillion kWh of electricity annually to power our heating and cooling systems, appliances and electronics. Although we pay for it all, a lot of that electricity is wasted. Tried-and-true solutions like weatherization and more efficient light bulbs will continue to be common sense solutions. But increasingly, homeowners, innovators, and policy makers are looking to leverage the average home’s 25 devices to reduce that waste.

Image courtesy U.S. Department of Energy

A homeowner installs a smart thermostat. Devices like this could be controlled though web platforms, along with water heaters, washing machines and LED bulbs with advanced controls.

Energy efficiency will play a key role in the Clean Power Plan

A new C2ES study outlines the significant role energy efficiency is expected to play in reducing carbon emissions from power plants under the proposed Clean Power Plan.

Energy efficiency can be an attractive way for states to meet the plan’s targets because, in addition to being relatively inexpensive to deploy on its own, energy efficiency reduces the need to build new, costly power plants in the future.

C2ES examined six economic modeling studies that project the likely impacts of the Clean Power Plan on the U.S. power mix and electricity prices. Despite starting with different assumptions, all of the studies project that energy efficiency will be the most used and least-cost option for states to implement the plan, and that overall electricity consumption will decline as a result.

The majority of the studies project either cost savings to power users under the Clean Power Plan or increases of less than $10 billion a year. That translates to less than $87 a year per household, or about 25 cents a day.

C2ES President Bob Perciasepe moderates a Solutions Forum panel with (l to r): Steve Harper, Global Director, Environment and Energy Policy, Intel Corporation; Alyssa Caddle, Principle Program Manager, Office of Sustainability, EMC; and Lars Kvale, Head of Business Development, APX Environmental Markets.

Our second Solutions Forum focused on how to spur more energy efficiency, especially through “intelligent efficiency” — a systems-based approach to energy management enabled through networked devices and sensors.

How can we use intelligent efficiency to reduce power sector emissions?

Nobody likes waste. And yet when we produce, distribute and use electricity, we’re wasting up to two-thirds of the energy.

Although we can’t eliminate all of these losses, we could reduce waste and increase reliability through “intelligent efficiency”— technology like networked devices and sensors, smart grids and thermostats, and energy management systems.

If we used energy more efficiently, we’d also reduce the harmful carbon dioxide emissions coming from our power plants — and reduce our electric bills.

That’s why energy efficiency is expected to be a critical, low-cost path for states looking to reduce power plant emissions under the proposed Clean Power Plan.

C2ES is pulling together top experts in sustainability, efficiency, and technology from cities, states and business to explore how we can deploy intelligent efficiency to help reach Clean Power Plan emissions targets. (RSVP for our event Monday, May 18, in Washington, D.C.)

Just as technology can instantly connect us with people across the globe or monitor our calories and whether we’re burning enough of them, we have technology that will allow us to network and monitor how we produce, deliver and consume electricity.