Climate

What We Learned About Climate Change In 2014, In 6 Scary Charts

CREDIT:

Multi-model Palmer Drought Severity Index (PDSI) for 2080-2099 in business-as-usual warming. Cross-hatching indicates cells where PDSI exceed -1 or +1 for at least 12 of the 15 models (80%). Via

This year saw a lot of big climate reports, including three by the U.N. Intergovernmental Panel on Climate Change (IPCC). And, as always, we had many important publications by individual scientists. And that means great charts, like the one from the IPCC above depicting the outcome of continued inaction on climate change. Here are some more of the year’s most impactful graphics.

The 2014 chart I consider the most important is not the prettiest or simplest. But it is the one that best captures our latest understanding of what has emerged as the greatest danger to humanity this century from human-caused climate change — Dust-Bowlification and the threat to our food supplies.

This map of the global drying we face uses the Palmer Drought Severity Index (PDSI), a standard measure of long-term drought. It is excerpted from the study, “Global warming and 21st century drying.”

Future drought

Palmer Drought Severity Index (PDSI) for 2080-2099 with business-as-usual warming. By comparison, during the 1930s Dust Bowl, the PDSI in the Great Plains rarely exceeded -3 (see here). Source: Cook et al. and Climate Progress.

We are currently on track to make drought and extreme drying the normal condition for the Southwest, Central Plains, the Amazon, southern Europe, and much of the currently inhabited and arable land around the world in the second half of the century.

Earlier this month, the U.K.’s Met Office updated its bar chart of the hottest years on record to include 2014, which is headed toward a new record.

globe_annual_ranked

Peter Stott, Head of Climate Attribution at the Met Office, explains: “Our research shows current global average temperatures are highly unlikely in a world without human influence on the climate.”

For those still under the fog of confusion spread by the climate science deniers, a new RealClimate chart in a recent post by climatologist Stefan Rahmstorf is especially elegant. This chart uses “change point” analysis, which “objectively looks for times in the data where the trend changes in a significant way.”

Change point

Global temperature (annual values, NASA GISTEMP data) together with piecewise linear trend lines from an objective change point analysis. (The value for 2014 will change slightly as it is based on Jan-Oct data only.) Graph by Niamh Cahill.

In its comprehensive literature review, the IPCC finds the annual cost of avoiding climate catastrophe is a mere 0.06 percent of annual growth — and that’s “relative to annualized consumption growth in the baseline that is between 1.6 percent and 3 percent per year.” So we’re talking annual growth of, say 2.24 percent rather than 2.30 percent to save billions and billions of people from needless suffering for decades if not centuries.

The IPCC has a simple chart/table spelling out this key finding:

Mitigation costs for 450 ppm

Global mitigation costs for stabilization at a level “likely” to stay below 2°C (3.6°F). The green columns show the consumption loss in the years 2030, 2050, and 2100 relative to a baseline without climate policy. The light green column shows the annual consumption growth reduction is 0.06 percent. Via IPCC.

The uncounted co-benefits are enormous. A recent International Energy Agency report concluded that “the uptake of economically viable energy efficiency investments has the potential to boost cumulative economic output through 2035 by USD 18 trillion.”

The report found that green building design can achieve health benefits — including reduced medical costs and higher worker productivity — “representing up to 75 percent of overall benefits.” That is, the non-energy benefits of efficiency upgrades can be three times larger than the energy savings.

The biggest scientific bombshell of 2014 was that the West Antarctic ice sheet appears close to if not past the point of irreversible collapse — and, relatedly, that “Greenland’s icy reaches are far more vulnerable to warm ocean waters from climate change than had been thought.”

We also learned in August that Greenland and West Antarctic Ice Sheet more than doubled their rate of ice loss in the last five years.

Those findings have led leading climatologists to conclude we are headed toward the high end of projected sea level rise this century, four to six feet. That means we are in a major coastal real estate bubble (see “When Will Coastal Property Values Crash“).

How big is the bubble and who will pay when it bursts? I’ll have more detail in a later post, but the terrific Reuters series, “The crisis of rising sea levels: Water’s Edge,” has a good chart:

Insurance

It’s a trillion-dollar bubble. And it looks like taxpayers — you and I — are on the hook for much of it.

If a picture is worth a thousand words, one good climate chart might be worth a thousand billion dollars.