Hot March, Melting Sea Ice, Record High CO2, and a Weak El Nino

Good afternoon everyone. It’s April 15 of 2019. And it’s high time I provided another update on the present global climate state.

(Indicators explained.)

Yes, I’ve been off this cart for a bit due to my personal climate action that I’m calling extreme clean. And I’ve got to say that this action is in solidarity with the tens of thousands of young people who continue to demonstrate for a more responsible political response to climate change around the world.

Action of all kinds is very important. But political action is where the rubber is really going to meet the solar and wind powered EV road of the future. It’s what’s going to help us navigate a necessarily fast clean energy transition away from the carbon spewing fuels of the present. And the fossil fueled politicians like Trump are going to have to be kicked out for that to happen.

(Human forced climate change loads the dice for stronger storms like Idai which devastated parts of Africa during March of 2019. Image source: NASA Worldview.)

At present, fossil fuel burning has really put us in a tough spot. That is the subject of today’s writing. Where we are today according to some major climate indicators — atmospheric CO2 (the primary greenhouse gas driving climate change), global surface temperature, Arctic sea ice, and the near term ENSO climate variability factor.

Atmospheric CO2 likely to hit between 413 and 415 ppm in May (monthly average)

For the first factor, atmospheric CO2 during recent days has risen to between 411 and 416 parts per million. This level is likely higher than at any time in at least the last 5 million years and is probably closer to ranges seen during the Middle Miocene around 15 million years ago. That’s pretty bad — implying about 2-3 C or more of global warming over the long term if those values aren’t somehow brought down.

(Present atmospheric CO2 levels are ranging between 411 and 416 parts per million on a daily basis at the Mauna Loa Observatory. These are the highest levels seen in at least 5 million years, possibly more. Image source: NOAA.)

Of course, due to the present pace of fossil fuel burning, atmospheric CO2 just keeps rising. Which is why a clean energy transition to get us to net zero and net negative carbon emissions is so, so important for our future.

CO2 isn’t the only greenhouse gas related to human activity. But according to agencies like NASA, it is the most important. Adding in other greenhouse gasses like Methane, NOx, and various other manufactured chemicals that trap heat, you end up with an atmospheric CO2 equivalent of approximately 497 ppm during 2019 (extrapolated from NOAA’s greenhouse gas index). This is a bit of a scary number for me as it implies that the top end indicator of all greenhouse gasses combined is about to move outside the Middle Miocene context soon.

Going back to the only slightly less scary CO2 figure, it appears likely that this primary greenhouse gas will top out at around 413 to 415 parts per million monthly average values during May of 2019. This indicator for annual peak values puts the present climate state increasingly out of the range of Pliocene past climates that many scientists are now researching as a corollary for present day climate impacts — at least on a greenhouse gas forcing basis.

March of 2019 was third hottest on record

It takes many decades and centuries for climates to balance out in response to a particular forcing. So present atmospheric warming driven by the greenhouse gasses mentioned above lag behind the initial global forcing. For this reason, on an annual basis, global temperatures are presently ranging between 1 and 1.2 degrees Celsius above 1880s averages as they continue to climb higher.

(The globe substantially heated up again during March — as seen in the above map provided by NASA. Image source: NASA GISS.)

These present departures roughly compare to temperatures during the Eemian climate epoch of about 120,000 years ago in which readings were 1 to 2 C warmer than 1880s averages. So we’re not yet in the Pliocene with regards to temperatures (2-3 C), but what we get long-term is probably the Miocene (3-4 C) if present greenhouse gas values remain stable. And we head for even more warming (4 C+) if we keep burning fossil fuels.

It’s in this rising temperature context that we are now experiencing more rapidly melting glaciers, ramping sea level rise, increasingly intense storms, wildfires and droughts, rising damage to corals, worsening heatwaves, more extinction pressure on plants and animals, and declining ocean health. It’s also worth pointing out that present temperatures are just a passing milestone on the way up if we keep burning fossil fuels and don’t learn how to pull down that excess atmospheric carbon.

(This graph of zonal temperature anomalies since 1880 is a visual representation of warming across the globe. These zones show various latitudes and their anomaly values vs mid 20th century averages over time. The long term warming trend is quite clear. Image source: NASA.)

According to NASA GISS, March of 2019 set its own benchmark as the third hottest such month on record. Temperatures for the month hit around 1.33 C above 1880s averages (1.11 C above NASA’s 20th Century baseline). This is pretty amazingly warm.

It was in this environment that the globe experienced a hyper-charged cyclone striking Africa, extensive damage due to flooding in the Central U.S., and recent very severe storms from the U.S. south through New England.

Arctic Sea Ice at Record Low for Recent Days

All this added heat has had its own impact on the Arctic where sea ice during recent days has plunged into new record low territory. According to information provided by the National Snow and Ice Data Center, Arctic sea ice yesterday measured just 13.518 million square kilometers. The lowest on record for today.

(Graph of Arctic sea ice measures for January through May of 2003 to present compared to the 1981 to 2010 average [gray line]. The orange line dipping below the pack is the measure for 2019. These are record lows for this time of year. Image source: NSIDC.)

That’s about 300,000 square kilometers below the previous record low set in 2017 and about 1.4 million square kilometers below the 1981 to 2010 average. A period in which major sea ice melt was already ongoing.

Sea ice melt doesn’t have a significant direct impact on sea level rise. You need land ice melt and ocean thermal expansion for that. But sea ice is a big ocean based heat reflector that helps to keep the Arctic environment stable and to prevent the world’s waters from sucking up an even greater amount of warming than they already do. That heat reflector is in decline and it’s one of the reasons why the Arctic is warming up at a faster rate than the rest of the globe.

(Early season sea ice melt is progressing through the Bering and Chukchi seas as overall Arctic sea ice extent hits record daily lows for this time of year. Image source: NASA Worldview.)

Major media appears to have recently had a bit of an epiphany about sea ice as recent reports from sources such as PBS note startling losses for the Bering region during 2019. It’s worth noting that individual seas tend to experience higher rates of ice variance. But the trend for the overall Arctic, which is the combination of all its incorporated seas, is one of consistent decadal sea ice decline.

Weak El Nino Means Uncertain Challenge to 2016 Record

While the world is heating up overall and experiencing many of the changes noted above, a shorter term variability feature of global temperature is the ENSO cycle. This periodic warming and cooling of Pacific Ocean surface waters relative to the globe sets down the rough markers of 3-5 year global temperature variability. During the Pacific cool phase, or La Nina, the global surface tends to cool off a bit. During the Pacific warm phase or El Nino, the global surface tends to warm.

This is not to be confused with total global heat gain — which is still occuring on a practically constant basis as oceans warm and glaciers melt in addition to atmospheric warming. It’s just a major factor in what we tend to see over the shorter term at the Earth’s surface.

(Present warmer than normal sea surface temperatures in the Equatorial Pacific indicate a weak El Nino. Image source: Earth Nullschool.)

For 2019, we are again tipping into the warmer side of this natural variability based trend. And combining that with the larger influence of human-forced warming, it appears that the dice are loaded for a challenge to the new record hot surface temperatures set in 2016.

But not so fast! 2019’s El Nino — or Pacific Ocean surface warming event — is, according to NOAA, likely to be rather weak. This compares to the Super El Nino event of 2016. So the swing toward warm side will tend to be relatively weaker. As a result, it’s less certain that 2019 will beat 2016 as hottest on record. And overall, it’s more likely that 2019 will place in the top 3 as 1st, 2nd or 3rd hottest (You may want to ask Dr Gavin Schmidt over at NASA GISS to see what he thinks. He’s been putting out some pretty accurate predictions over the past few years.).

So far, according to NASA GISS, December, January and February of climate year 2019 came in as 3rd hottest. With the weak El Nino ramping up, it does appear that March, April, May could heat up as well. We shall see!

Living in a rapidly warming world

Looking at all of these shorter term indicators, it’s easy to miss the bigger context. That being — we are living in a world in which atmospheric greenhouse gasses are rapidly increasing. These gasses, in turn, are causing the world to rapidly warm resulting in surprising changes and increasing damage. And it’s in this context that climate action on the part of individuals, businesses and governments becomes all the more necessary.

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Posted by robertscribbler on April 15, 2019

https://robertscribbler.wordpress.com/2019/04/15/hot-march-melting-sea-ice-record-high-co2-and-a-weak-el-nino/