Kevin Trenberth in Science Magazine, August 2015:

The main pacemaker of variability in rates of GMST increase appears to be the PDO, with aerosols likely playing a role in the earlier big hiatus. There is speculation whether the latest El Niño event and a strong switch in the sign of the PDO since early 2014 (see the figure) mean that the GMST is stepping up again. The combination of decadal variability and a trend from increasing greenhouse gases makes the GMST record more like a rising staircase
than a monotonic rise. As greenhouse gas concentrations rise further, a negative decadal trend in GMST becomes less likely ( 13). But there will be fluctuations in rates of warming and big regional variations associated with natural variability. It is important to expect these and plan for them.

Paul Kantner now deceased at 74.

The newest Yale Video is looking like one of the more impactful in the series, given that it lays a two by four upside of one of denialdom’s most cherished myths, that satellite temperature data, or more specifically, satellite data since the 1998 El Nino event, are the one and only gold standard measure of whether the planet is gaining heat.

I’ve made a few cosmetic changes in the version above, added in an updated temperature graph to reflect that we now have finalized 2015 – and some, I hope, helpful graphics and animations to emphasize a few points of science-speak. (and I’ve uploaded to the Climate Denial Crock of the Week channel on YouTube, because so many of those subscribers, bless their hearts, still don’t know that I’m working with Yale for the last 4 years…)

One of the main points made by Andy Dessler, Carl Mears, and Ben Santer, is that temperature records of any kind would be suspect if they were not congruent with the actual behavior of biological and physical systems on the planet – many of which can be measured completely independently of one another – and so provide a useful check on each other.

The best example of this in the science literature is a famous 2008 paper from NASA’s Cynthia Rosenzweig and her team, in which more than 29,000 data sets of physical and biological processes are analyzed.


Observed impacts included changes to physical systems, such as glaciers shrinking, permafrost melting, and lakes and rivers warming. Biological systems also were impacted in a variety of ways, such as leaves unfolding and flowers blooming earlier in the spring, birds arriving earlier during migration periods, and plant and animal species moving toward Earth’s poles and higher in elevation. In aquatic environments such as oceans, lakes, and rivers, plankton and fish are shifting from cold-adapted to warm-adapted communities.

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In November, the International Energy Agency quietly dropped this bombshell projection: “Driven by continued policy support, renewables account for half of additional global generation, overtaking coal around 2030 to become the largest power source.”

The IEA notes, “With 60 cents of every dollar invested in new power plants to 2040 spent on renewable energy technologies, global renewables-based electricity generation increases by some 8,300 TeraWatt-hours (more than half of the increase in total generation).” That increase is “equivalent to the output of all of today’s fossil-fuel generation plants in China, the United States and the European Union combined.” It represents new investment of some $7 trillion in renewables over the next quarter century.

Significantly, this remarkable projection about the future of electricity is simply what the IEA believes is now going to happen given the pledges made in Paris by the world’s leading countries to rapidly expand renewable energy investment while restraining and, in many cases, reducing carbon pollution from fossil fuels through 2030. This is IEA’s “central scenario,” and in it the planet still warms 2.7°C by 2100 and more after that.

In short, this projection is not what would happen if the nations of world pursued the kind of aggressive policies they unanimously agreed to in Paris to avoid very dangerous warming and stay below total warming of 2°C. That would effectively end fossil fuel emissions by 2100.

Undereported story – Congress extended incentives for renewable energy.


Back in December, Congress did something it rarely does any more these days — struck a series of compromises and passed a bill, specifically a giant $1.8 trillion spending bill.

Among many other things, that bill extended the two key federal tax credits that support renewable energy: the production tax credit (PTC), which mostly goes to wind, and the investment tax credit (ITC), which goes to solar. Read the rest of this entry »


An interesting and tense moment at December’s American Geophysical Union conference came with an all star panel of climate scientists and energy experts, and clear lines were drawn between the “must have nuclear’ faction, lead by James Hansen, and the “renewables can do it” faction, represented by Mark Jacobson of Stanford – who I interviewed the same day – more on that soon.

New research seems to support Jacobson.


Analysts have long argued that nations aiming to use wind and solar power to curb emissions from fossil fuel burning would first have to invest heavily in new technologies to store electricity produced by these intermittent sources—after all, the sun isn’t always shining and the wind isn’t always blowing. But a study out today suggests that the United States could, at least in theory, use new high-voltage power lines to move renewable power across the nation, and essentially eliminate the need to add new storage capacity.

This improved national grid, based on existing technologies, could enable utilities to cut power-sector carbon dioxide emissions 80% from 1990 levels by 2030 without boosting power prices, researchers report today in Nature Climate Change.

The findings come on the heels of the Paris climate agreement, in which the United States pledged to cut its national emissions by up to 28% from 2005 levels by 2025. About 40% of U.S. emissions come from the power sector, and the U.S. Environmental Protection Agency (EPA) recently released rules that task states with reducing power-sector emissions. States can choose from a menu of strategies, EPA says, such as boosting renewable energy use.

But some observers wonder whether the U.S. power grid can rise to the renewables challenge. The grid is divided into several regional grids or “interconnections,” which contain smaller subdivisions. Because regions experience both sunless and windless periods, energy planners and experts have long believed that a wind- and solar-dominated grid would need to store some power for later use. The problem is that large-scale storage technologies haven’t been commercially realistic.

Alex MacDonald, a National Oceanic and Atmospheric Administration (NOAA) in Washington, D.C., researcher, was familiar with that problem. But he realized that researchers hadn’t explored all the potential solutions. For instance, meteorological data suggest that wind is always blowing somewhere in the United States, MacDonald says. So, although renewable energy output might be intermittent on a regional scale, it would have a more constant flow at a national scale. MacDonald wondered whether the U.S. grid might be able to overcome intermittency problems if it added high-voltage, direct-current (HVDC) transmission lines—which suffer less energy loss than do traditional alternating-current transmission lines—to connect regional grids, so that power could be moved to where it was needed.


The study also suggests the U.S. may make the transition without heavy investment in energy-storage technologies, which are seen by some as essential for helping to smooth out the intermittent flows from wind and solar farms.

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Part 3 from my interview with Dr Mears, whose work was prominently misused during the recent hearing chaired by Senator Ted Cruz.