The Relentless March

Click to enlarge.

by Gaius Publius

Just a reminder, now that we're sending U.S. crude oil to other countries — so that other countries can count our carbon extraction against their emissions totals, to their climate blame and our financial gain — time does indeed march on.

As do global temperature increases. The valuable Greg Laden has the story:

Global Warming In November

The NASA GISS global temperature anomaly for November has been published. ...

The huge uptick we saw during the last part of the current year is the result of global warming, which has been pushing temperatures up, and the current El Nino, which probably started to affect these measurements in late September. Over the next few months or so, El Nino proper will start to decline, but the surface temperatures will remain elevated by El Nino (there is a lag). After that, we should see monthly temperature readings being to drop, but the overall trend is likely to continue.

The graphic at the top of the page is the 12 month moving average from the NASA GISS data base, up through November. Notice that since the 1960s there has been a very steady upward trend, with some variation. Most of the big upward spikes you see are El Nino years, and the lower troughs are typically periods with one or more La Nina events. These variations reflect the interaction between surface (air and sea surface) and the ocean, mainly the Pacific.

2015 is currently the warmest year on record, and 2014 is the second warmest year. It is virtually impossible for 2015 to drop below warmest once December values are added in. Likely, the spread between warmest and second warmest year will increase. 

Two small points about the graph. First, as Laden notes (my emphasis), "This is hundreds of a degree C anomaly, the standard number used to report, off of a baseline. The baseline in the case of NASA GISS is 1951-1980, which does not represent pre-industrial levels." This means that on the Y-axis, the change in temperature from "0" is measured from temperatures in the 1960s, not the 1880s. If you look at the whole range expressed by the chart, you're seeing a temperature change of about –0.4°C to about +0.8°C — a range of 1.2°C. Except for a few post-war decades, this is indeed a relentless march.

Second, Laden tells us that the big changes this year are partly due to the recent El Niño, something that comes and goes. The trend, however, won't change:

The huge uptick we saw during the last part of the current year is the result of global warming, which has been pushing temperatures up, and the current El Nino, which probably started to affect these measurements in late September. Over the next few months or so, El Nino proper will start to decline, but the surface temperatures will remain elevated by El Nino (there is a lag). After that, we should see monthly temperature readings being to drop, but the overall [upward] trend is likely to continue.

The relentless march. Feeling lucky?

GP