NASA recently stirred a minor controversy with a release proclaiming 2014 as the warmest year on record. The claim was picked up by President Obama in last week’s State of the Union speech.
Not so fast, according to Berkeley Earth, an independent climate think tank in California. It said 2014 was only “nominally” the warmest because “within the margin of error, it is tied with 2005 and 2010 and so we can’t be certain it set a new record.”
Either way, though, the 2014 numbers extend a pattern of record-high global temperatures since 1998 — a period that has produced the 10 warmest years in recorded global temperature in modern times.
And the variance in temperature over this period has been quite small, especially when measurement error is taken into account.
In contrast, the earth’s temperature rose measurably over the previous 20 years, by about one degree Fahrenheit, a rate that over 100 years would produce 5 or 6 degrees of warming, or roughly 3 degrees Celsius. Forecasts based on the warming trend from about 1980 to 2000 are a major source of climate alarm. The International Panel on Climate change has said increases above 2 degrees Celsius could have catastrophic effects.
The pause in the rate of warming in recent years has caused some consternation among climate scientists seeking to understand its causes. And that debate is far from over.
It is also notable that global warming is not evenly distributed. According to the National Oceanic and Atmospheric Administration, last year was only the 34th warmest in the contiguous United States since 1895.
These facts, however, are not reasons for complacency on climate change.
Of particular concern, especially in coastal areas (like here, for instance), the oceans continue to grow warmer. Berkeley Earth reports that the average ocean temperature for 2014 set a record by “a clear amount,” that the 10 highest annual ocean temperatures are all recent and that the upward trend in ocean heat stretches back a century.
Similarly, the Arctic Sea-Ice Monitor, a collaborative effort of the University of Alaska at Fairbanks and the Japanese government, has shown that the extent of Arctic Sea ice has been shrinking since the 1980s and is on track to record the lowest levels yet during this decade.
With this kind of record it is frustrating to see national governments, including that of the U.S., still quarreling, mostly fruitlessly, over limits on carbon dioxide emissions.
In the meantime, reducing the release of methane, a short-lived but potent warming agent, into the atmosphere could help slow sea-level rise.
President Barack Obama recently announced an initiative to cut methane emissions from U.S. oil and gas production by 45 percent in the next six years. That goal is welcome — as far as it goes — although oil and gas companies already have a powerful cost incentive to reduce emissions on their own.
Meanwhile, the rising scientific recognition of the potential — and relatively rapid — benefits from cutting soot emissions remains largely overlooked. That “black carbon” pollution is generated from the burning of wood and diesel fuel.
A cooperative international effort with binding targets for methane and soot abatement is needed to have a significant impact on these warming agents.
As for the dwindling ranks of those who deny global — and ocean — warming, don’t take our word for it.
Just check out those rising sea levels.