How long do we have?

The March 2019 temperature is in line with an earlier analysis that 2019 could be 1.85°C warmer than preindustrial and that a rapid temperature rise could take place soon, as illustrated by the image below.

A catastrophe of unimaginable proportions is unfolding. Life is disappearing from Earth and all life could be gone within a decade. At 5°C of warming, most life on Earth will have disappeared. When looking at near-term human extinction, 3°C will likely suffice. Study after study is showing the size of the threat, yet many people seem out to hide what we're facing.

Above image asks 'How long do we have?' The image is created with NASA LOTI data, adjusted 0.78°C to reflect a 1750 baseline, ocean air temperature and higher polar anomaly. Trends are added based on 1880-2019 (purple) and 2000-2019 data (red). The long-term purple trend points at 2025 as the year when 3°C rise from preindustrial could be crossed, while the red trend that focuses on short-term events shows how a 3°C rise from preindustrial could be reached as early as in 2020.

The chart below shows elements contributing to the warming, adding up to a rise of as much as 18°C by 2026.

[ from an earlier post ]

The situation is dire and calls for comprehensive and effective action, as described at the Climate Plan.

If we accept that crimes against humanity include climate crimes, then politicians who inadequately act on the unfolding climate catastrophe are committing crimes against humanity and they should be brought before the International Criminal Court in The Hague, the Netherlands.

Links

• Co-extinctions annihilate planetary life during extreme environmental change, by Giovanni Strona and Corey Bradshaw (2018)
https://www.nature.com/articles/s41598-018-35068-1

• How much warming have humans caused?
https://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• A rise of 18°C or 32.4°F by 2026?
https://arctic-news.blogspot.com/2019/02/a-rise-of-18c-or-324f-by-2026.html

• Stronger Extinction Alert
https://arctic-news.blogspot.com/2019/03/stronger-extinction-alert.html

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

The Methane Threat

Carbon dioxide levels in the atmosphere are accelerating. As illustrated by the image below, a linear trend hardly catches the acceleration, while a polynomial trend does make a better fit. The polynomial trend points at CO₂ levels of 437 ppm by 2026.

EPA animation: more extreme heat

This worrying acceleration is taking place while energy-related have been virtually flat over the past few years, according to figures by the EIA and by the Global Carbon Project. So, what makes growth in CO₂ levels in the atmosphere accelerate? As earlier discussed in this and this post, growth in CO₂ levels in the atmosphere is accelerating due to continued deforestation and soil degradation, due to ever more extreme weather events and due to accelerating warming that is making oceans unable to further take up carbon dioxide.

Ocean warming is accelerating on the Northern Hemisphere, as illustrated by above image, and a warmer Atlantic Ocean will push ever warmer water into the Arctic Ocean, further speeding up the decline of the sea ice and of permafrost.

[ click on images to enlarge ]

Loss of Northern Hemisphere snow cover is alarming, especially in July, as depicted in above image. The panel on the left shows snow cover on the Northern Hemisphere in three areas, i.e. Greenland, North America and Eurasia. The center panel shows North America and the right panel shows Eurasia. While Greenland is losing huge amounts of ice from melting glaciers, a lot of snow cover still remains present on Greenland, unlike the permafrost in North America and especially Eurasia, which has all but disappeared in July.

[ for original image, see 2011 AGU poster ]

Worryingly, the linear trend in the right panel points at zero snow cover in 2017, which should act as a warning that climate change could strike a lot faster than many may expect.

A recently-published study warns that permafrost loss is likely to be 4 million km² (about 1.5 million mi²) for each 1°C (1.8°F) temperature rise, about 20% higher than previous studies. Temperatures may well rise even faster, due to numerous self-reinforcing feedback loops that speed up the changes and due to interaction between the individual warming elements behind the changes.

[ Arctic sea ice, gone by Sept. 2017? ]

One of the feedbacks is albedo loss that speeds up warming in the Arctic, in turn making permafrost release greenhouse gases such as carbon dioxide, nitrous oxide and methane.

Higher temperatures on land will make warmer water from rivers enter the Arctic Ocean and trigger wildfires resulting in huge emissions including black carbon that can settle on sea ice.

Given the speed at which many feedbacks and the interaction between warming elements can occur, Arctic sea ice volume may decline even more rapidly than the image on the right may suggest.

[ Record sea ice volume anomalies since end 2016 ]

Ominously, sea ice volume anomalies have been at record levels for time of year since end 2016 (Wipneus graph right, PIOMAS data).

As the Gulf Stream pushes warmer water into the Arctic Ocean, there will no longer be a large buffer of sea ice there to consume the heat, as was common for the entire human history.

Moreover, forecasts are that temperatures will keep rising throughout 2017 and beyond.

The Australian Bureau of Meteorology reports that seven of eight models indicate that sea surface temperatures will exceed El Niño thresholds during the second half of 2017.

The image on the right, by the ECMWF (European Centre for Medium-Range Weather Forecasts), indicates an El Niño that is gaining strength.

For more than half a year now, global sea ice extent has been way below what it used to be, meaning that a huge amount of sunlight that was previously reflected back into space, is now instead getting absorbed by Earth, as the graph below shows.

[ Graph by Wipneus ]

Where can all this extra heat go? Sea ice will start sealing off much of the surface of the Arctic Ocean by the end of September 2017, making it hard for more heat to escape from the Arctic Ocean by entering the atmosphere.

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

It looks like much of the extra heat will instead reach sediments at the seafloor of the Arctic Ocean that contain huge amounts of methane in currently still frozen hydrates.

[ click on image to enlarge ]

The danger is that more and more heat will reach the seafloor and will destabilize methane hydrates contained in sediments at the bottom of the Arctic Ocean, resulting in huge methane eruptions.

As the image on the right shows, a polynomial trend based on NOAA July 1983 to January 2017 global monthly mean methane data, points at twice as much methane by 2034. Stronger methane releases from the seafloor could make such a doubling occur much earlier.

Meanwhile, methane levels as high as 2592 ppb were recorded on April 17, 2017, as shown by the image below. The image doesn't specify the source of the high reading, but the magenta-colored area over the East Siberian Sea (top right) looks very threatening.

We already are in the Sixth Mass Extinction Event, given the rate at which species are currently disappearing from Earth. When taking into account the many elements that are contributing to warming, a potential warming of 10°C (18°F) could take place, leading to a rapid mass extinction of many species, including humans.

[ Graph from: Which Trend is Best? ]

How long could it take for such warming to eventuate? As above image illustrates, it could happen as fast as within the next four years time.

The situation is dire and calls for comprehensive and effective action, as described at the Climate Plan.


Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• How much warming have humans caused?
https://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

• Accelerating growth in CO₂ levels in the atmosphere
https://arctic-news.blogspot.com/2017/02/accelerating-growth-in-co2-levels-in-the-atmosphere.html

• An observation-based constraint on permafrost loss as a function of global warming, by Chadburn et al. (2017)
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3262.html

• Reduction of forest soil respiration in response to nitrogen deposition, by Janssens et al. (2010)
http://www.nature.com/ngeo/journal/v3/n5/full/ngeo844.html

• Methane Erupting From Arctic Ocean Seafloor
https://arctic-news.blogspot.com/2017/03/methane-erupting-from-arctic-ocean-seafloor.html

• Warning of mass extinction of species, including humans, within one decade
https://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html

Which Trend Is Best?

NASA just released temperature data for February 2017. Should we be worried? Yes, there are many reasons to be very worried.

Let's go back in time. This is from a post written ten years ago:
We may suddenly face a future in which many if not most people will have little or no access to food, water, medicines, electricity and shelter, while diseases go rampant and gangs and warlords loot and devastate the few livable areas left. Human beings as a species will face the risk of total extinction, particularly if many species of animals and plants that humans depend on will disappear. The post continues: Many people are still in denial about the severity of the problem of global warming, the accumulation of dangers and their progression. 

Indeed, even today many people will still deny that such events could strike suddenly, e.g. within a few years time. Many people use linear trends to predict the future many years from now. As an example, the straight blue line on the graph below is a linear trend based on NASA 1880-current meteorological stations data. The problem is that linear trends, especially when based on data that go back many years, can make people overlook important recent changes such as the temperature rise that has taken place over the past few years, the decline of glaciers and sea ice and the recent increases in concentrations of carbon dioxide in the atmosphere.

[ click on image to enlarge ]

An alternative approach is to use recent data, e.g., from the year 2012, and then calculate a polynomial trend that extends a few years into the future. Taking such an approach can result in a polynomial trend (red curved line) that is contained in the NASA Land+Ocean data from January 2012 to February 2017. This trend shows the potential for a 10°C (18°F) rise four years from now, and this should act as a powerful warning.

The appropriateness of linear versus non-linear trends was also discussed earlier at the Controversy page.

In addition to looking at trends that are contained in such data, it makes sense to analyse the different elements contributing to such a rise. Such elements are discussed in more detail at the extinction page, which confirms the potential for a 10°C temperature rise within years, i.e. by the year 2026.

The situation is dire and calls for comprehensive and effective action as described in the Climate Plan.


Links

• Climate Plan
http://arctic-news.blogspot.com/p/climateplan.html

• Ten Dangers of Global Warming
http://arctic-news.blogspot.com/p/ten-dangers-of-global-warming.html

• Extinction
http://arctic-news.blogspot.com/p/extinction.html

• Controversy
http://arctic-news.blogspot.com/p/controversy.html

• Warning of mass extinction of species, including humans, within one decade
http://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html

More than 2.5m Sea Level Rise by 2040?

A warming period more than 400,000 years ago pushed the Greenland ice sheet past its stability threshold (which may have been no more than several degrees above pre-industrial temperatures). This resulted in a nearly complete deglaciation of southern Greenland, raising global sea levels some 4.5-6 meters, found a recent study by Reyes et al. Due to melting elsewhere, global mean sea level then was 6 to 13 metres above the present level. Indeed, melting of the entire West Antarctic Ice Sheet can add a further 6-meter rise in sea levels. If the East Antarctic Ice Sheet (EAIS) were to melt as well, sea levels would rise by around 70 metres.

Sea level is now rising by 3.1mm (0.122 inch) per year. Much of this rise is due to rising temperatures, but there are also other factors. One quarter of the rise results from groundwater depletion, while run off from melting ice and glaciers adds another quarter and the remainder is attributed to thermal expansion of sea water. Furthermore, as temperatures rise, feedbacks start to kick in, e.g. the kinetic energy from stronger waves and more intense storms can speed things up.

Clearly, a rapid multi-meter rise would be devastating as it would flood many coastal cities, as well as much of the land now used to grow food. By how much have sea levels been rising recently and how fast can they be expected to rise in the near future?

NASA image, data by the JPL PODAAC, in support of the NASA's MEaSUREs program.

Sea levels have risen by some 60 mm over the past 20 years, as above NASA image shows, which has a linear trendline added. The question is whether a linear trendline is the most appropriate trendline, given that it suggests that a similar rise could be expected over the next 20 years. A polynomial trendline appears to fit the data better, as the animation below shows.

Such a polynomial trendline, however, points at a similar rise (of some 50 mm) in just four years time, with an even more steeper rise to follow, as illustrated by the image below.

And indeed, such a rise doesn't slow down there. A polynomial trendline applied to the data points at a sea level rise of more than 2.5 m (8.2 ft) by the year 2040.

The image below gives an idea of what a sea level rise of six feet (1.829 m) would do to the City of New York. Of course, this is only the sea level rise. Storm surge would come on top of this, as discussed at Ten Dangers of Global Warming.

So, what would be more appropriate, to expect sea levels to continue to rise in a linear way, or to take into account feedbacks that could speed things up? Where such feedbacks could lead to is illustrated by the image below.

[ from: How many deaths could result from failure to act on climate change? click on image to enlarge ]

This calls for comprehensive and effective action, as discussed at the Climate Plan blog.


References

- South Greenland ice-sheet collapse during Marine Isotope Stage 11, Reyes et al. (2014)
http://www.nature.com/nature/journal/v510/n7506/full/nature13456.html

- Nonsustainable groundwater sustaining irrigation: A global assessment, Yoshihide Wada et al. (2012)
http://onlinelibrary.wiley.com/doi/10.1029/2011WR010562/abstract

- Groundwater Depletion Linked to Rising Sea Levels
http://www.waterworld.com/articles/2010/11/groundwater-depletion-linked-to-rising.html

- Assessment of the Jason-2 Extension to the TOPEX/Poseidon, Jason-1 Sea-Surface Height Time Series for Global Mean Sea Level Monitoring, Beckley et al. (2010)
http://www.tandfonline.com/doi/abs/10.1080/01490419.2010.491029

- Feedbacks in the Arctic
http://climateplan.blogspot.com/p/feedbacks.html

- How many deaths could result from failure to act on climate change? (2014)
http://arctic-news.blogspot.com/2014/05/how-many-deaths-could-result-from-failure-to-act-on-climate-change.html

Post by Sam Carana.

How much will temperatures rise?

Runaway Global Warming

If we take the NASA Annual Mean Land-Ocean Temperatures and draw a projection into the future, temperatures will quickly be 3 degrees Celsius higher than the base period (1951-1980), i.e. well before 2050, as illustrated on image 1. below. 

Image 1. Temperatures will be 3 degrees Celsius higher well before 2050

Above projection appears to be steeper than even the worst-case scenario pictured by the IPCC for years, such as on the image below.

Image 2. from IPCC 2001. Projections of globally averaged surface temperature 2000-2100 are shown for six SRES scenarios and IS92a using a model with average climate sensitivity. The grey region marked "several models all SRES envelope" shows the range of results from the full range of 35 SRES scenarios in addition to those from a range of models with different climate sensitivities. The temperature scale is departure from the 1990 value.

Could temperatures rise faster in future than what the IPCC anticipated in 2001? The answer must be yes! In 2007, the IPCC described that, even if greenhouse gas concentrations in the atmosphere were stabilized for 100 years at year 2000 values (B1), then we would still be committed to a further warming of 0.5°Celsius. This committed warming should not be confused with ‘unavoidable climate change’ over the next half century, which would be greater because forcing cannot be instantly stabilized. And of course, as it turned out, emissions have not been stabilized at 2000 values, but have in fact increased substantially.

As it turned out, the models used by the IPCC made all kinds of assumptions that didn't eventuate. But before deciding to instead settle for a relatively simple extrapolation of observed data, there are some issues that require a further look.  

As discussed in the earlier post Accelerated Arctic Warming, temperatures in the Arctic have been rising at a much faster pace than global temperatures, and if this accelerated rise continues, we can expect a 10 degrees Celsius rise in the Arctic before 2040, as illustrated by image 3. below.  

Image 3. Three kinds of warming - 2: Accelerated warming in the Arctic 

Such a temperature rise in the Arctic will undoubtedly lead to additional greenhouse gas emissions in the Arctic, of carbon dioxide, nitrous oxide and particularly methane, threatening to trigger runaway global warming. 

The image below, from the methane-hydrates blog, combines these three kinds of warming, showing global temperatures that soon catch up with accelerated Arctic warming, as heatwaves at high latitudes will cause wildfires, in particular in Siberia, where firestorms in peat-lands, tundras and forests could release huge amounts of emissions, including soot, much of which could settle on the Himalayan plateau, darkening the ice and snow and resulting in more local heat absorption. Rapid melt of glaciers will then cause flooding at first, followed by dramatic decreases in the flow of river water that up to a billion people now depend on for water supply and irrigation.

In other words, the situation looks much more dire than what most models make us believe; the more reason to adopt the climate plan that is also described at the post at the methane-hydrates blog.

Image 4. Three kinds of warming - 1, 2 and 3 

References

- IPCC (TAR) - Climate Change 2001: Synthesis Report

http://www.grida.no/publications/other/ipcc_tar/?src=/climate/ipcc_tar/vol4/english/figspm-10b.htm

- IPCC (AR4) - Climate Change 2007: Working Group I: The Physical Science Basis

http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-es-16-radiative-forcing.html#10-es-17-climate-change

- Accelerated Arctic Warming

http://arctic-news.blogspot.com/2013/01/accelerated-arctic-warming.html

- Methane hydrates

http://methane-hydrates.blogspot.com/2013/04/methane-hydrates.html

PIOMAS data confirm exponential trend

The Applied Physics Laboratory/Polar Science Center at the University of Washington has issued an extra release of Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) data.

Sea ice volume on August 25th, 2012, was 3500 km³, or about 500 km³ less than the prior minimum, reached on September 10th, 2011.

The image below shows that recent data for 2012 appear to match almost perfectly the expected values based on exponential trends added by Wipneus.

The image below, again based on PIOMAS data, shows trends added by Wipneus for each month of the year. The black line shows the average for the month September, pointing at zero a bit into the year 2015, while the average for August and October (the overlapping red and dark blue lines, appearing as a single purple line) point at zero before the start of the year 2016.

In conclusion, it looks like there will be no sea ice from August 2015 through to October 2015, while a further three months look set to reach zero in 2017, 2018 and 2019 (respectively July, November and June). Before the start of the year 2020, in other words, there will be zero sea ice for the six months from June through to November.

And, events may unfold even more rapidly, as discussed earlier at Getting the picture.

The image below, from the Naval Research Laboratory, shows the dramatic decline of sea ice thickness over the last 30 days.