Arctic News: January 2018

Monday, January 22, 2018

2017 was hottest year on record

The year 2017 was the hottest year on record, as the image below illustrates.

When determining which year was the hottest year, care should be taken to avoid bias due to temporary conditions such as the El Niño that was present in 2016 and the La Niña we're now experiencing now. Above image uses NASA land+ocean January 2012-December 2017 anomalies from 1951-1980, adjusted by 0.59°C to cater for the rise from preindustrial to 1951-1980, to calculate a linear trend that goes some way to smooth out variability due to El Niño/La Niña events. The trend shows that 2017 was significantly warmer than 2016.

The trend also shows that 1.5°C above preindustrial was crossed back in 2016. This 1.5°C (or 2.7°F) was set at the Paris Agreement as a guardrail that was not to be crossed. The trend further shows that we've meanwhile crossed 1.6°C above preindustrial and we look set to cross the 2°C guardrail within years.

Global warming has crossed 1.5°C / 2.7°F above preindustrial and looks set to cross 2°C / 3.6°F soon. Due to accelerating warming in the Arctic, that could happen within one or two years time, i.e. much faster than the trendlines below may suggest.

Indeed, warming in the Arctic is taking place much faster than elsewhere, and the difference is accelerating. There's a huge danger that accelerating warming in the Arctic will speed up feedbacks such as:
• huge amounts of methane getting released from the seafloor of the Arctic Ocean;
• melting of sea ice and permafrost causing more sunlight to get absorbed in the Arctic, as less sunlight gets reflected back into space;
• changes to jet streams causing more extreme weather, in turn resulting in more emissions, such as due to wildfires;
• and more.

In conclusion, feedbacks could speed up global warming by much more than what may be suggested by above trends that look only at surface temperature of the atmosphere and that are based on previous data when such feedbacks had yet to become manifest.

Add up the impact of all warming elements and, as an earlier analysis shows, the rise in mean global temperatures from preindustrial could be more than 10°C in a matter of years, as illustrated by the image below, which shows a much steeper rise.

Particularly devastating feedbacks could result from changes regarding heat and carbon dioxide taken up by oceans. Oceans now take up 93.4% of global warming, as illustrated by the image below.

As said, when looking at surface temperatures of the atmosphere, there will be bias due to El Niño/La Niña events. One way to smooth out such bias is by calculating trendlines over many years. Another way to compensate for such bias is to also look at ocean heat. In terms of ocean heat, the year 2017 stands at the top, as the left panel of above image illustrates. In 2016, El Niño caused relatively more heat to be present in the atmosphere and less in oceans, whereas the opposite occurred in 2017, contributing to the fact that in 2017 a record amount of ocean heat was recorded. Occurrence of El Niño/La Niña events over the years is visualized by the image below.

One danger is that, in future, there will be more impact by El Niño events and less by La Niña events. A recent study concludes that as temperatures rise due to emissions by people, the frequency, magnitude and duration of strong El Niño events will increase.

In addition to higher temperature peaks due to El Niño events, more heat could remain in the atmosphere as the rise in temperature in general causes greater ocean stratification, making that less heat gets absorbed by oceans, as discussed in several earlier posts. The image below depicts this feedback and further feedbacks mentioned above. Feedbacks are described in more detail at the feedbacks page.

The situation is further illustrated by the danger assessment below.

[ Danger Assessment, from earlier post ]

Meanwhile, the Global Carbon Project projects a growth of 2% for the 2017 global carbon dioxide emissions from fossil fuels and industry (including cement production), compared to 2016 levels, as illustrated by image below.

Tuesday, January 2, 2018

Unfolding Arctic Catastrophe

On January 1, 2018, methane levels as high as 2764 ppb (parts per billion) were recorded. The solid magenta-colored areas near Greenland indicate that this very high reading was likely caused by methane hydrate destabilization in the sediments on the seafloor of the Arctic Ocean.

The state of the sea ice is behind this. On January 1, 2018, Arctic sea ice extent was at record low for the time of the year. The smaller the extent, the less sunlight gets reflected back into space and is instead absorbed in the Arctic.

At this time of year, though, hardly any sunshine is reaching the Arctic. So, what triggered this destabilization? As the image below indicates, year-to-date average Arctic sea ice volume has been at record low in 2017, which means that there has been very little sea ice underneath the surface throughout 2017.

Warm water will melt the sea ice from below, which keeps the water at greater depth cool. However, when there is little or no sea ice underneath the surface, little or no heat will be absorbed by the process of melting and the heat instead stays in the water, with the danger that it will reach sediments at the bottom of the Arctic Ocean, as illustrated by the image below.

The Buffer has gone, feedback #14 on the Feedbacks page

[ image from: Warming is accelerating ]

The image on the right shows warm water from the North Atlantic arriving near Svalbard. How warm is the water beneath the surface of the Arctic Ocean? The image below gives an indication, showing how much warmer the water was from October 1, 2017, to December 30, 2017, at selected areas near Svalbard, where warm water from the North Atlantic dives under the sea ice of the Arctic Ocean, carried by the Gulf Stream.

[ click on images to enlarge ]

In 1981-2011, temperatures were gradually falling by more than one degree Celsius from October 1 to the December 21 Solstice, then started to rise again in line with the change in seasons (blue line). In 2017, temperatures were rising in October. On October 25, 2017, the sea surface was as warm as 17.5°C or 63.5°F, i.e. a 14.1°C or 24.5°F anomaly. On average, it was 12.96°C or 23.35°F warmer during the period from October 1 to December 30, 2017 (red line), compared to the same days in 1981-2011.

The images below further illustrate the situation. Surface temperature of the atmosphere near Svalbard was as warm as 7°C or 44.5°F on January 13, 2018 (at green circle, left panel). The sea surface near Svalbard was as warm as 15.9°C or 60.8°F on January 12, 2018, compared to 2.4°C or 36.4°F on January 12 for the period 1981-2011 (at green circle, center panel). Waves as high as 13.04 m or 42.8 ft (at green circle, right panel) batter the North Atlantic along Norway's coast all the way to Svalbard on January 15, 2018.

The image below shows that waves as high as 16.01 m or 52.5 ft are forecast to batter the North Atlantic on January 16, 2018 (green circle, left panel). 100% relative humidity is recorded over the Arctic Ocean on January 15, 2018 (green circle, center panel). The Jet Stream reaches speeds as high as 426 km/h or 264 mph on January 15, 2018 (green circle, right panel).

Similar extreme weather patterns can be seen elsewhere in the Arctic. The image below on the left shows that temperatures as high as 18.5°C or 65.3°F were recorded on Jan. 14 and 15, 2018 in Metlakatla, Alaska. The image below on the right shows that surface temperatures as high as 7.4°C or 45.2°F were reached on January 16, 2018, in Yukon Territory, Canada (at green circle).

[ click on images to enlarge ]