Carbon dioxide emissions are rising

CO₂ emissions are rising

In models used by the Intergovernmental Panel on Climate Change (IPCC), carbon dioxide (CO₂) emissions were expected to come down in line with pledges made at the Paris Agreement. Yet, the Global Carbon Project projects growth in CO₂ emissions from fossil fuels and industry in 2018 to be +2.7%, within uncertainty margins from +1.8% to +3.7%.

This rise is in line with an image from an earlier post that shows growth of CO₂ in the atmosphere to be accelerating.

[ Growth of CO₂ in ppm, based on annual Mauna Loa data (1959-2017), with 4th-order polynomial trend added ]

Methane emissions rising as well

And it's not just CO₂ emissions that are rising. Methane emissions are rising as well. Sadly, politicians typically ignore this elephant in the room, in particular seafloor methane emissions that threaten to trigger a huge temperature rise within years.

[ ignoring the elephant in the room, i.e. seafloor methane ]

The MetOp image below shows high methane levels over oceans on December 9, 2018, pm, at 469 mb. Levels over the Arctic Ocean in particular are very high, as the large areas solidly colored magenta indicate.

The MetOp image shows many areas where no data were available, as indicated by the color grey. The NPP images don't have as many grey areas. The image below confirms very high methane levels over the Arctic Ocean on December 9, 2018 pm, closer to the surface, i.e. at 840 mb. While there still are many grey areas, the absence of data for many of them is due to altitude, since large parts of Greenland, Antarctica and the Himalayas are rather high.

As discussed in earlier posts, large amounts of methane appear to be rising from the Arctic Ocean. As the methane rises higher in the atmosphere, it moves closer to the Equator. The NPP image below shows levels at 399 mb on December 9, 2018, pm. At this altitude, there are very few grey areas, so it's possible to get a fuller picture of where the highest levels of methane are. Ominously, levels as high as 3060 ppb were reached.

El Niño events will intensify

The image on the right shows that, on December 30, 2018, sea surface temperature anomalies were as high as 9.7°C or 17.4°F in the Pacific Ocean, 11.1°C or 20°F in the Atlantic Ocean and 17.1°C or 30.8°F near Svalbard in the Arctic Ocean.

NOAA expects El Niño to form and continue through the Northern Hemisphere winter 2018-19 (~90% chance). A recent study concludes that global warming will enhance both the amplitude and the frequency of eastern Pacific El Niño events.

Albedo change

Albedo change due to decline of the snow and ice cover is another feedback that the IPCC has yet to come to grips with. The IPCC seems to have hoped that albedo loss in the Arctic was somehow compensated for by albedo gain in the Antarctic.

The IPCC (in AR5, WG1) did find a significant increase in Antarctic annual mean sea ice extent that is very likely in the range of 1.2 to 1.8 % per decade between 1979 and 2012 (0.13 to 0.20 million km² per decade) (very high confidence).

As the image below shows, global sea ice extent steadily came down, but then grew somewhat until end 2014. From end 2014 on, Antarctic sea ice extent fell rapidly, with huge repercussions for global sea ice extent, as also illustrated by the image on the right that highlights the most recent years of the graph below.

At the end of 2016, Antarctic sea ice extent was a lot smaller than it was at the end of 2014. Such a difference in sea ice extent corresponds with a huge difference in radiative forcing (RF).

Antarctic sea ice extent was 4.913 million km² on January 5, 2019, a record low for the time of year and 4.212 million km² less than it was on January 5, 2015, when extent was 9.125 million km².

This decline could make a difference of 1.3 W/m² in RF. By comparison, the IPCC estimated the net RF from all emissions by people from 1750 to 2011 at 1.6 W/m².

As the image below shows, global sea ice extent was at a record low for the time of year on Dec. 28, 2018, and looks set to go lower in 2019.

Antarctic sea ice decline is only part of the picture, there's also Arctic sea ice decline and there's decline of the snow and ice cover on land.

Joint impact

A lot of this has not been accounted for by the IPCC, i.e. the recent increases in CO₂ emissions, increases in methane releases, increases in further emissions such as nitrous oxide and black carbon, albedo changes due to decline in the snow and ice cover and associated changes such as jet stream changes, more permafrost melting and stronger impacts of future El Niño events.

The image on the right shows the joint impact of the warming elements that threaten to eventuate over the next few years and that could result in a 10°C or 18°F global temperature rise in a matter of years.

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

Links

• Global Carbon Project
http://www.globalcarbonproject.org

• Looking the climate abyss in the eye!
https://arctic-news.blogspot.com/2018/09/looking-the-climate-abyss-in-the-eye.html

• How much warmer is it now?
https://arctic-news.blogspot.com/2018/04/how-much-warmer-is-it-now.html

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

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

• Albedo change in the Arctic
http://arctic-news.blogspot.com/2012/07/albedo-change-in-arctic.html

• IPCC AR5 WG1 chapter 4
https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_Chapter04_FINAL.pdf

• The Threat
https://arctic-news.blogspot.com/p/threat.html

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

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

• NOAA El Niño forecast
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

• El Niño events to become stronger and more intense
https://www.theage.com.au/environment/climate-change/el-nino-events-to-become-stronger-and-more-intense-study-finds-20181212-p50lrv.html
https://www.nature.com/articles/s41586-018-0776-9

Dangerous situation in Arctic

In the North Pacific, the flow of warmer water is clearly visible (see images right, green circle left).

In the North Atlantic, huge amounts of heat are moving into the Arctic Ocean (green circle right).

At some spots, heat that is traveling underneath the sea surface comes to the surface (green circle at the top).

Most warming caused by people's emissions goes into oceans, especially into the top layer of oceans.

Furthermore, warmer air and warmer sea surfaces can cause winds to grow dramatically stronger. As the Arctic is warming much faster than the rest of the world, the narrowing difference between the temperatures at the North Pole and the Equator is decreasing the speed at which winds circumnavigate Earth; at the same time, the amount of heat that is moving north can grow dramatically, both due to winds and sea currents, and cyclones can further accelerate this.

The danger is that an influx of warm salty water will reach the seafloor and trigger methane eruptions.

The situation is especially critical in many parts of the Arctic Ocean where the water is very shallow. Some 75% of the East Siberian Arctic Shelf (ESAS) is shallower than 50 m (see maps on the right).

[ warm water from the Atlantic Ocean is
increasingly invading the Arctic Ocean ]

The danger here is huge, for numerous reasons, incl.:

• shallow waters can warm up very rapidly in case of an influx of warm water;

• these shallow seas are now covered by ice, so the heat cannot escape to the atmosphere;

• sea ice is very thin, so the sea ice won't act as a buffer to absorb the heat;

• methane rising through shallow waters will pass through the water column and enter the atmosphere more quickly;

• in shallow waters, large abrupt releases will more quickly deplete the oxygen in the water, making it harder for microbes to break down the methane;

• hydroxyl levels over the Arctic are very low, which means that it takes much longer for methane over the Arctic to get broken down.

The four videos below provide a good introduction into the various issues and illustrate how dangerous the situation is in the Arctic.

Each video is part of a talk between Dave Borlace and Peter Wadhams.

Part 1 discusses albedo change in the Arctic and associated changes such as jet stream changes.

Part 2 discusses the threat of huge methane releases in the Arctic.

Part 3 discusses the thermohaline circulation and methods that could improve the situation such as carbon removal and Ocean Mechanical thermal Energy Conversion (OMTEC).

Part 4 discusses sea level rise and fires.

The situation is dire and calls for comprehensive and effective action, as described at the Climate Plan, i.e. multiple lines of action implemented in parallel and locally where possible.


Links

• As El Niño sets in, will global biodiversity collapse in 2019?
https://arctic-news.blogspot.com/2018/11/as-el-nino-sets-in-will-global-biodiversity-collapse-in-2019.html

• Doomsday by 2021?
https://arctic-news.blogspot.com/2018/11/doomsday-by-2021.html

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

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

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

• Seismic Events
https://arctic-news.blogspot.com/p/seismic-events.html

• Can we weather the Danger Zone?
https://arctic-news.blogspot.com/2018/07/can-we-weather-the-danger-zone.html

• How much warmer is it now?
https://arctic-news.blogspot.com/2018/04/how-much-warmer-is-it-now.html

• What Does Runaway Warming Look Like?
https://arctic-news.blogspot.com/2018/10/what-does-runaway-warming-look-like.html

• Peaks Matter
https://arctic-news.blogspot.com/2018/08/peaks-matter.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

As El Niño sets in, will global biodiversity collapse in 2019?

Global biodiversity collapse

[ Will global biodiversity collapse in 2019? ]

A recent study created a dataset of plant temperature tolerances with a median upper tolerance limit of 23.7°C.

This temperature is about 10°C higher than the temperature in the year 1750.
Only during times of mass extinctions were temperatures that high, such as during the PETM, 55.5 million years ago, and the Permian–Triassic extinction event, 252 million years ago, also know as the Great Dying when some 95% of species known from fossils went extinct.

[ image from: How much warmer is it now? ]

The study concludes that extinction will already occur far earlier than when upper tolerance levels are reached, as "loss of one species can make more species disappear (a process known as ‘co-extinction’), and possibly bring entire systems to an unexpected, sudden regime shift, or even total collapse."

There was a small group of species with large tolerance limits and remarkable resistance to environmental change, but even they could not survive co-extinctions. In fact, their extinction was abrupt and happened far from their tolerance limits and close to global biodiversity collapse at around 5°C of heating.

[ El Niño sets in ]

In the top image on the right, monthly NASA Land+Ocean temperature data 2017-October 2018 are adjusted, and a polynomial trend is added, showing how a 5°C rise in temperature could occur very rapidly, i.e. by September 2019.

The second image on the right is from an earlier post that contains more background on the adjustment of NASA data and the need for a polynomial trend.

A strong abrupt rise in temperature could be caused by an influx of warm salty water into the Arctic Ocean, as this can trigger large eruptions of methane from its seafloor, as discussed in earlier posts such as this one and as further discussed below.

As El Niño sets in, the odds that such rapid warming will threaten to cause global biodiversity collapse are rising.

Earthquakes triggering methane releases

An additional danger is that large methane releases from the seafloor of the Arctic Ocean will be triggered by earthquakes.

The danger is that isostatic rebound will trigger earthquakes in the Arctic Ocean that this in turn will destabilize methane hydrates, as discussed in more detail at this page.

Seismic shocks can travel over long distances along fault lines and destabilize methane hydrates in other locations.

Above image shows that on November 9, 2018, an earthquake with a magnitude of 6.8 on the Richter scale occurred on the fault line between Greenland and Norway.

This area is not used to be hit by large earthquakes. No larger earthquake has occurred in this area for more than 100 years.

Subsequent earthquakes did occur nearby, on November 12, 13 and 15, respectively measuring M4.3, M4.6 and M5.2 on the Richter scale, which also are very large earthquakes to hit this area.

Ominously, high levels of methane showed up on November 21, 2018, over the Greenland Sea (top image on the right).

Earlier, high levels of methane had been recorded over the Arctic Ocean. Note that this fault line runs across the Arctic Ocean toward the Laptev Sea.

Methane levels as high as 2787 ppb were recorded on November 15, 2018 (second image on the right).

On November 17, 2018, methane levels as high as 2847 ppb were recorded (third image on the right).

On November 20, 2018, methane levels as high as 2827 ppb were recorded (fourth image on the right).

The images show large methane levels over the East Siberian Arctic Shelf, the submarine permafrost north of Eastern Siberia.

In a 2008 paper, Dr. Natalia Shakhova et al. concluded that release of up to 50 Gt of methane from hydrates storage could occur at any time, an amount many times the methane that is now present in the atmosphere.

Additional emissions

Such a temperature rise would trigger many forest fires, releasing huge amounts of additional emissions, including carbon dioxide, methane and black carbon.

The image on the right shows carbon dioxide levels in California as high as 809 ppm on November 10, 2018 (at the green circle).

The next image on the right illustrates the jump in carbon dioxide levels in Mauna Loa, Hawaii, following the the fires in California.

“Levels of heat-trapping greenhouse gases in the atmosphere have reached another new record high,” the World Meteorological Organization (WMO) said in a recent news release. “There is no sign of a reversal in this trend, which is driving long-term climate change, sea level rise, ocean acidification and more extreme weather.”

“The science is clear. Without rapid cuts in CO₂ and other greenhouse gases, climate change will have increasingly destructive and irreversible impacts on life on Earth. The window of opportunity for action is almost closed,” said WMO Secretary-General Petteri Taalas.

“The last time the Earth experienced a comparable concentration of CO₂ was 3-5 million years ago, when the temperature was 2-3°C warmer and sea level was 10-20 meters higher than now,” said Mr Taalas.

“CO₂ remains in the atmosphere for hundreds of years and in the oceans for even longer. There is currently no magic wand to remove all the excess CO₂ from the atmosphere,” said WMO Deputy Secretary-General Elena Manaenkova.

In the associated video, Dr Oksana Tarasova added that “changes in carbon dioxide levels that we are observing now do not happen naturally. Such changes never ever happened in the history of this Planet.”

As the image on the right shows, CH₄, CO₂ and N₂O levels in the atmosphere are, respectively, 257%, 146% and 122% their 1750 levels.

How fast could 5°C warming happen? 

The U.S. Global Change Research Program has just released its Fourth National Climate Assessment. One of its key messages is that temperatures could rise by 5°C or more. The report adds that this could occur by the end of the century, but the report doesn't deny this could also occur much earlier. Indeed, one of its key findings is that some feedbacks and potential state shifts cannot be quantified; and some are probably still unknown.

What the report doesn't mention is that global biodiversity will have collapsed at 5°C of warming. Such a rise kills all plants on land and thus virtually all mammals (including humans), since they either directly or indirectly feed on plants.

A rapid 5°C rise could occur if an influx of warm salty water triggered methane eruptions from the seafloor of the Arctic Ocean. Combined with snow and ice loss, it could rapidly raise temperatures by 1.5°C, which increases water vapor. If cloud feedback is strongly positive, water vapor feedback can lead to 3.5 times as much warming, so these warming elements alone could cause 5°C warming within years. And then, of course, there are further warming elements.

The situation is dire and calls for comprehensive and effective action, as described at the Climate Plan, i.e. multiple lines of action implemented in parallel and locally where possible. Of course, as long as politicians remain reluctant to even consider pursuing efforts to reduce emissions, the world can be expected to remain in the Danger Zone for a long time to come.


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

• Greenhouse gas levels in atmosphere reach new record, World Meteorological Organization (WMO)
https://public.wmo.int/en/media/press-release/greenhouse-gas-levels-atmosphere-reach-new-record

• WMO video - Press Conference: Greenhouse Gas Bulletin (Geneva, 22 November 2018)
http://webtv.un.org/watch/wmo-press-conference-greenhouse-gas-bulletin-geneva-22-november-2018/5970414543001/

• Fourth National Climate Assessment - U.S. Global Change Research Program
https://nca2018.globalchange.gov/

• Doomsday by 2021?
https://arctic-news.blogspot.com/2018/11/doomsday-by-2021.html

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

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

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

• Seismic Events
https://arctic-news.blogspot.com/p/seismic-events.html

• Can we weather the Danger Zone?
https://arctic-news.blogspot.com/2018/07/can-we-weather-the-danger-zone.html

• How much warmer is it now?
https://arctic-news.blogspot.com/2018/04/how-much-warmer-is-it-now.html

• What Does Runaway Warming Look Like?
https://arctic-news.blogspot.com/2018/10/what-does-runaway-warming-look-like.html

• Peaks Matter
https://arctic-news.blogspot.com/2018/08/peaks-matter.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

Doomsday by 2021?

The Doomsday Clock, by the Bulletin of the Atomic Scientists, constitutes a potent symbol of the danger we're in. When taking the 'minutes to midnight' from statements 1991 to 2018, an added trend points at Midnight by 2021. Will it be Doomsday by 2021?

The 2018 Statement said that "world leaders failed to respond effectively to the looming threats of nuclear war and climate change. [ . . ] Global carbon dioxide emissions have not yet shown the beginnings of the sustained decline towards zero that must occur if ever greater warming is to be avoided."

Recently, Fatih Birol, IEA Executive Director, said: "We expect energy-related CO2 emissions will increase once again in 2018 after growing in 2017."

Next to carbon dioxide, the outlook for other greenhouse gases is also very worrying and the situation could deteriorate very rapidly, as further described below.

[ click on images to enlarge ]

Here's how. As above image shows, oceans continue to warm up, due to the rise in greenhouse gas levels in the atmosphere. 

[ wind speed as high as 268 km/h or 167 mph ]

The image on the right shows sea surface temperature anomalies as high as as 7.1°C (or 12.7°F) in the Bering Strait (at the green circle) on October 15, 2018.

Warmer oceans result in stronger cyclones. The next image on the right shows that Typhoon Yutu was forecast to reach an Instantaneous Wind Power Density (WPD) as high as 207647 W/m² at 850 mb and wind speeds as high as 268 km/h or 167 mph at the green circle, i.e. at 18.50° N, 124.00° E, on October 30, 2018, 00:00 UTC.

Cyclones can suddenly push huge amounts of salty warm water into the Arctic Ocean.

On November 12, 2018, there was a sudden influx of warm water from the Atlantic Ocean near Svalbard and sea surface temperature was as high as 20.4°C or 68.7°F, i.e. 17.4°C or 31.4°F warmer than in 1981-2011.

[ warm water from the Atlantic Ocean is
increasingly invading the Arctic Ocean ]

As the image on the right also illustrates, warm salty water from the Atlantic Ocean is increasingly invading the Arctic Ocean.

Salinity levels at the surface of the Arctic Ocean are low, due to the increasingly large run-off from rivers, glaciers, etc. Also, the Arctic Ocean is increasingly receiving precipitation from the Atlantic Ocean, due to stronger winds over the North Atlantic.

All this contributes to the formation of a freshwater lid on top of the surface of the Arctic Ocean, which has in turn helped to keep sea ice extent larger than it would otherwise have been over the past few years.

The influx of water from the Atlantic Ocean has a much higher salinity level. Ice will stay frozen and will not melt in freshwater until the temperature reaches 0°C (or 32°F). Ice in saltwater on the other hand will already have melted away at -2°C (or 28.4°F).

The danger is that a strong influx of salty warm water will reach the seafloor of the Arctic Ocean and trigger destabilization of hydrates in sediments resulting in massive eruptions of methane from the seafloor of the Arctic Ocean, as described in earlier posts such as this one.

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

Arctic sea ice is currently widening in extent, in line with the change of seasons. This means that less heat can escape from the Arctic Ocean to the atmosphere. Sealed off from the atmosphere by sea ice, greater mixing of heat in the water will occur down to the seafloor of the Arctic Ocean, while there is little or no ice buffer left to consume an influx of heat from the Atlantic and Pacific Oceans, increasing the danger that warm water will reach the seafloor of the Arctic Ocean and destabilize methane hydrates.

This methane could cause temperatures to suddenly rise strongly at the higher latitudes of the Northern Hemisphere, speeding up decline of sea ice and permafrost, and further deforming the jet stream.

This could trigger even more extreme weather events, in particular storms, flooding, heatwaves and fires, across the Northern Hemisphere that could devastate crops, take down power grids and threaten meltdowns of nuclear power plants.

Aerosols associated with fires could further push up temperatures, as described in more detail below.

[ Image from: Extreme weather is upon us ]

Burning of agricultural waste can cause a lot of air pollution. The image on the right shows that on November 7, 2018 (at the green circle), levels of coarse particulate matter (PM₁₀) as high as 1,913 μg/m³ were reached.

Even higher levels can be reached due to forest fires. As the image on the right shows, PM₁₀ levels as high as 6,289 µg/m³ were reached on November 10, 2018, levels as high as 9,116 µg/m³ were reached on November 11, 2018, and levels as high as 9,856 µg/m³ are forecast for November 14, 2018, due to fires in California.

Above image shows that levels as high as 75,994 μg/m³ were reached in Siberia in 2017.

Such fires can add huge amounts of black carbon to the atmosphere.

For comparison, the EPA has set a National Ambient Air Quality Standard PM₁₀ maximum of 150 μg/m³.

The decreasing temperature difference between the North Pole and the Equator would make the jet stream even more wavy, accelerating winds that increase fire risks, while also increasing droughts that further increase fire risks.

High greenhouse gas levels further aggravate the situation. Carbon monoxide (CO) levels as high as 52,440 ppb and carbon dioxide (CO₂) levels as high as 809 ppm were reached on November 10, 2018, while CO levels as high as 78,116 ppb were forecast for November 14, 2018, due to fires in California.

The image below shows the smoke from fires in California on November 9, 2018.

Black carbon causes both cooling and warming. Black carbon shades the surface, somewhat cooling the surface of land and water, while it also absorbs heat, thus warming the air above the surface. Furthermore, black carbon causes warming by darkening the surface once it settles down. Studies have calculated that black carbon has a total net global warming effect of more than 1.1 W/m².

Above video Rings of Fire features former firefighter Tom Swetnam.

The image below illustrates to what extent smoke from fires boosted black carbon in the air over North America on August 23, 2018.

[ Image from: Will August 2018 be the hottest month on record? ]

Furthermore, without access to fossil fuel and with the electricity grid down, many people could turn to kerosene lamps for lighting and burning wood for heating and cooking, resulting in even more black carbon emissions that have a huge immediate warming impact. James Hansen (2007) found the GWP for soot (BC) to be approximately 2000 for 20 years, approximately 500 for 100 years and approximately 200 for 500 years.

Next to black carbon, there is another type of aerosols that is important, i.e. sulfur.  Above video contains the Horizon documentary 'Global Dimming', broadcast January 2005 by the BBC.

Above image shows sulfur dioxide levels as high as 3597.10 µg/m³ in East Asia on October 24, 2018, indicating that sulfur levels may still be rising.

[ From the Extinction page ]

The image on the right shows IPCC (2000) projections for sulfur dioxide emissions.

The aerosol masking effect associated with sulfur would be strongly reduced as industrial activity would come to a standstill, thus further driving up warming.

The events as described above could result in a combined additional warming due to changes in aerosols of up to 2.5°C (4.5°F) in a matter of years.

In conclusion, the prospect of such a sequence of events makes a Doomsday-by-2021 warning appropriate. The accumulated impact of the various warming elements is illustrated by the image on the right.

A recent study found upper tolerance limits in plants of 23.7°C, which is less than where Earth would end up with a 10°C rise from current temperatures. However, these are tolerance levels, rather than extinction levels. The study concludes that "loss of one species can make more species disappear (a process known as ‘co-extinction’), and possibly bring entire systems to an unexpected, sudden regime shift, or even total collapse." The study therefore puts global diversity collapse at around 5°C of heating.

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


Links

• The Doomsday Clock by the Bulletin of the Atomic Scientists
https://thebulletin.org/doomsday-clock/

• What Does Runaway Warming Look Like?
https://arctic-news.blogspot.com/2018/10/what-does-runaway-warming-look-like.html

• Tweet by Fatih Birol, IEA Executive Director, October 8, 2018
https://twitter.com/IEABirol/status/1049249280073113600/photo/1

• Climate change and trace gases, by James Hansen et al. (2007)
http://rsta.royalsocietypublishing.org/content/365/1856/1925

• IPCC Special Report, Emissions Scenarios (2000)
http://www.ipcc.ch/ipccreports/sres/emission/index.php?idp=140

• EPA National Ambient Air Quality Standards
https://www.epa.gov/criteria-air-pollutants/naaqs-table
https://www.epa.gov/air-trends/particulate-matter-pm10-trends

• Toxic smog cloaks New Delhi morning after Diwali festivities (November 8, 2018)
https://phys.org/news/2018-11-toxic-smog-cloaks-delhi-morning.html

• Extreme weather is upon us
https://arctic-news.blogspot.com/2017/09/extreme-weather-is-upon-us.html

• Will August 2018 be the hottest month on record?
http://arctic-news.blogspot.com/2018/08/will-august-2018-be-the-hottest-month-on-record.html

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

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

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

• Can we weather the Danger Zone?
https://arctic-news.blogspot.com/2018/07/can-we-weather-the-danger-zone.html

• How much warmer is it now?
https://arctic-news.blogspot.com/2018/04/how-much-warmer-is-it-now.html

• Peaks Matter
https://arctic-news.blogspot.com/2018/08/peaks-matter.html

• Disappearance of Arctic Sea Ice

https://arctic-news.blogspot.com/2018/07/disappearance-of-arctic-sea-ice.html

• Warming is accelerating

https://arctic-news.blogspot.com/2017/11/warming-is-accelerating.html

• Accelerating Warming of the Arctic Ocean

https://arctic-news.blogspot.com/2016/12/accelerating-warming-of-the-arctic-ocean.html