Climate Change Monthly Checkup: April 20, 2017


Home / Climate Change Monthly Checkup: April 20, 2017

For the period January through March, 2017 is cooler than 2016 — but hotter than any other year. Graphic courtesy of NOAA.

Earth’s climate is running a persistent fever. Elevated temperatures are increasingly accompanied by disruptive weather events. Medicine is being delivered in small doses, but it may not be enough to keep the patient’s condition from deteriorating.

This monthly column will be devoted to what changes the earth’s climate is experiencing and what is being done to mitigate the effects.

Publication will come a day after the issuance of NOAA’s Global Analysis for the previous month, normally around the 19th. This report will also cover the most recent sea surface temperatures, atmospheric carbon dioxide measurements, and other matters pertinent to climate change/global warming.

Temperatures so far in 2017 are lower than those for the comparable period of 2016. However, that shouldn’t lead to complacency, as 2016 was juiced by a powerful El Niño. Conditions in the Pacific Ocean are now ENSO (El Niño/Southern Oscillation) neutral. Considering the water temperatures in the equatorial Pacific Ocean, global land and sea temperatures are surprisingly warm.

We’re Number Two; We’re Number Two

NOAA tracks land and sea temperatures in nine categories: global land, global sea, global land and sea; and each of the three categories by hemisphere. March 2017 was the second warmest March since record-keeping began in 1880 in seven of the nine categories. Northern hemisphere land and southern hemisphere land were both third.

January to March temperatures set records in many parts of the world. Graphic courtesy of NOAA.

Warmth was not uniform over the earth — it never is. We will be looking specifically for trends that indicate significant changes in temperature or precipitation that could disrupt agriculture, habitation, and commerce.

A single month is not as representative of temperature trends as longer periods. The January to March 2017 period shows that new records for the first quarter of the year were set in the following places:

  • Eastern Australia
  • Eastern Russia
  • Mexico and adjacent U.S.
  • South Indian Ocean adjacent to southern Africa.
  • Western tropical Pacific Ocean
  • Parts of the South Pacific Ocean

The only place that was significantly below average was in the western Pacific Ocean. Nowhere was it record cold.

The Relationship Of ENSO To Global Temperature

The relationship between ENSO and global temperature is clear. Graphic courtesy of NOAA.

The accompanying graphic clearly shows the effect of ENSO on global temperature: Every El Niño is related to warmer temperatures and every La Niña to cooler temperatures.

During the recent El Niño, global temperatures surpassed one degree Celsius above the 20th century average — half way to the 2 C that most scientists believe is a dangerous threshold — for the first time.

March of 2017 was the first month in which the temperature was more than 1 C above average in a non-El Niño month. This should be considered a significant and potentially dangerous milestone.

To make an honest extrapolation of temperature into the future, comparisons should be made with comparable years. Just eyeballing a best-fit in the accompanying chart yields an approximate rate of change of 0.3 C (0.5 F) per 20 years. This number pops out when we use El Niño, La Niña, and neutral years separately. That extrapolates to 1 C in about 70 years — not such a long time in which to change the trajectory of global temperature.

Latest Sea Surface Temperatures

Conditions in the central Pacific are ENSO neutral, but anomalies exist elsewhere. Graphic courtesy of NOAA.

The ENSO data clearly show that water temperature in one small part of the world has an effect on global temperature.

El Niño is a well-known phenomenon that comes and goes in an irregular cycle that is hard to predict. In general, much less is known about oceanic circulations than atmospheric ones: there are many more reporting stations on land than sea; almost no observations are available from the deep ocean.

NOAA releases sea surface temperature data twice every week. The most recent map is from April 17, 2017 and shows a warm pool in the eastern equatorial Pacific which appears to be complicit in the recent flooding rains in Colombia and Peru.

Elsewhere, there are cold pools (anti-blobs) in the Gulf of Alaska and south of Greenland/Iceland. The former is a reversal from the pattern that persisted during the California drought; the latter may be a permanent feature that reflects the effect of cold, fresh water from melting glaciers.

The predominance of warm water equatorward of 40 degrees latitude in both hemispheres is noticeable, as is the colder water north and south of the 40th parallels.

One feature that has persisted for many months is the ribbon of much warmer than normal water from the coast of North Carolina east-northeastward to south of Labrador. This may just be a temporary displacement of the Gulf Stream — or something more permanent.

Decoded Science will follow trends in sea surface temperatures from month to month.

Atmospheric Carbon Dioxide Continues To Rise

Carbon dioxide measurements on Mount Mauna Loa set daily and weekly records recently. Graphic courtesy of NOAA.

Atmospheric carbon dioxide, deemed by all credible scientists to be a major factor in global warming, is subject to local sources. To get a true reading of global changes in atmospheric carbon dioxide, scientists shiver on top of Mount Mauna Loa in Hawaii, 14 thousand feet above sea level. The readings they get still vary somewhat, but are considered representative to very high accuracy.

It is well-accepted that carbon dioxide in the atmosphere at the start of the industrial revolution was in the neighborhood of 280 parts per million (ppm). Since then it has risen steadily to over 400 ppm. On April 16, a new daily record of 409.52 was set, and the most recent weekly average was also a record.

Carbon dioxide varies with the season, as large amounts of vegetation in mid- and high latitudes of the northern hemisphere grow — consuming carbon dioxide — and die. The yearly maximum is in May, as plants begin to bloom in profusion for the summer.

Multi-Billion Dollar Disasters

In the first three months of 2017, there were five weather events that caused more than a billion dollars in damages; last year there were four. Before that, no year had more than 2 such events in the first quarter of the year.

Most forecasts that use various parameters for temperature increase in the future predict more storms and more powerful storms.

Please let Decoded Science know what effects of global warming you see.

Leave a Comment