Climate Compass Blog

Save money, help the environment with a solar power purchase agreement

We’re going solar!

Our middle-class, suburban family of five, with two children in college, two mortgages and a pile of other consumer debt, is getting a brand new, 7 kilowatt photovoltaic rooftop system worth roughly $31,000 – without us paying a penny out of pocket.

That’s right. We’re paying nothing upfront for the ability to generate up to one-third of the electricity our 1,500-square-foot split-foyer home would use in a typical month.

How’s that possible? With a power purchase agreement.

Pope Francis highlights the moral imperative of climate action

Photo Courtesy  Xiquinho Silva, via Flkickr

St. Peter's Square

Pope Francis brings a clear and powerful moral voice to a climate change debate too often clouded by competing ideologies. He reminds us of our responsibilities to the planet and to one another, and makes plain the stakes and the urgency of stronger action.

Pope Francis’ encyclical, a top-level teaching document to more than 1 billion Roman Catholics worldwide, builds on a foundation of accepted science that tells us the Earth is warming and that human activity is the primary cause.

But he is speaking to all of us, not only the Catholic faithful, about our core values – especially our duty to care for the Earth and all those who live on it.

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.