A highlight of recent research supporting the climate realist perspective #2

I have come across three scientific papers published recently, all of which support the climate realist perspective, and thought them of such significance that I should share them here, in my climate realist paper update series.

Seemingly with every passing week, I see more and more papers supporting the climate realist perspective. Many such studies can be found in the lists of significant papers on this blog (most papers on such lists support the climate realist perspective), but since some don’t have a list yet or won’t in the future, I will report on at least some of them in blog posts. Just this week, for example, I have seen recent research arguing for national climate change driven by direct thermal emissions from energy consumption, (related to the urban heat island effect, press release here)

eft2126-fig-0002

Energy consumption (heat output) versus national climate change of Japan and the United Kingdom. Note that energy consumption seems to predict national climate change better than the CMIP5 climate models. From Murray and Heggie 2016.

a natural cause of recent cooling in the North Atlantic (press release here), and a strong reduction in atmospheric blocking (which causes cold outbreaks like the episode in early 2014with future warming. All of these support the climate realist perspective, since climate realists accept that the urban heat island effect has a significant warming effect on the climate, the thermohaline circulation is not shutting down because of human-caused warming, and cold outbreaks will not get worse and more frequent with further warming.

Why the Arctic’s methane isn’t a catastrophic time bomb waiting to happen

There has been much concern over the possibility of a powerful positive feedback from melting arctic ice (caused by human warming of the arctic), in this case the rapid release of massive quantities of methane from below the surface into the atmosphere. Since methane is a very potent greenhouse gas, this would amplify the warming significantly and possibly cause dangerous, runaway climate change. This idea is supported by what I think is a minority view in the scientific literature, with many papers arguing against such alarm. Despite this, papers like this made waves in the media with claims of $60 trillion damages from the “methane time bomb”, as it has become known. Such claims are very unlikely, and were disputed hotly in the journal in which they were published. Furthermore, papers that do not even cite Whiteman et al. 2013 point to a less threatening situation. I will cover them here.

methanegraphic_feb2011_640

First is Near-surface permafrost degradation: How severe during the 21st century? This paper argues that a massive release of methane from melting arctic permafrost is dubious.

Second is Ancient Permafrost and a Future, Warmer Arctic. This paper reports that permafrost in subarctic Canada has survived interglacial periods which were warmer and lasted longer than the present one. This would imply that, at least to a certain degree of warming, much arctic permafrost will survive.

Third is Shrub expansion may reduce summer permafrost thaw in Siberian tundra. This paper argues that arctic shrub growth, which is expected with warming, may partially offset future permafrost thawing.

Fourth is Fluxes and fate of dissolved methane released at the seafloor at the landward limit of the gas hydrate stability zone offshore western Svalbard. This paper argues than most methane released from the seabed in Svalbard does not reach the atmosphere, preventing it from contributing to warming. There is a press release for the paper here.

Fifth is Extensive release of methane from Arctic seabed west of Svalbard during summer 2014 does not influence the atmosphere. This paper’s conclusions are similar to the fourth’s: that most methane being released from the Svalbard seabed does not reach the atmosphere. There is a press release for the paper here.

Sixth is No significant increase in long-term CH 4 emissions on North Slope of Alaska despite significant increase in air temperature. This paper argues that despite a significant increase in air temperature on the North Slope of Alaska, there has not been a significant increase in methane emissions. This means, they argue, that the arctic may not contribute significantly to methane emissions in the future if they continue at this trajectory. There is a press release for the paper here.

Seventh is Over-estimating climate warming-induced methane gas escape from the seafloor by neglecting multi-phase flow dynamics. This paper argues that by neglecting dynamics of seafloor methane, analyses can overestimate by orders of magnitude the amount of methane that will escape to the surface and provide a positive feedback.

So, in conclusion, though melting arctic ice may emit some methane into the atmosphere, the effect most likely will not be highly significant and virtually certainly not catastrophic.

Some remarks on the recent record warmth

UPDATE: The global temperature seems to have been taking quite a hit over the past two months, as it fell rapidly from April to May, and from May to June (this is according to UAH satellite data, RSS data is not yet public at the time of writing). This raises the interesting possibility of 2016 not being the warmest year on record in the satellite data, because it probably will be in surface temperatures.

Let me first say that if humans were the only input on the climate system, then we would probably see a steady warming and every month and year would be a new record. That global temperatures have been rising is not a

surprise to me. However, the climate system isn’t linear and we are definitely not the only factor. That being said, I believe that human-caused global warming will not manifest itself (and hasn’t) as sudden, enormous jumps in temperature. It is more likely, in my opinion, to be represented as a steady warming of the climate system from human input of greenhouse gases, urbanization, land use change, etc. The idea that human-induced climate change is responsible for temperature jumps like those above is absurd. I don’t think that

without human influence we’d be seeing a temperature increase like the one above, but claiming that humans are responsible for this kind of a jump is ridiculous, especially when we have seen jumps like this in the past precisely during an El Nino event, such as during the El Nino of 1997-1998, which was (as is this current one) one of the strongest such events on record. So, while humans are definitely responsible for a significant part of the warming we’re seeing and have seen in the past 150 years and because of humans we will experience more record temperatures, El Nino is the dominant cause of this temperature jump. In addition, if there hadn’t been an El Nino over the past two years, the earth may have cooled due to the combined effect of various natural effects, such as low solar activity and declining PDO and AMO. This is not to say that natural forces will always overwhelm human warming, but over multiyear and even longer periods, natural variability (which is still very poorly understood) can cancel or even reverse the human-caused warming.