carbon emissions

Time to Cool It: The U.N.’s Moribund High-End Global Warming Emissions Scenario

The amount of future warming is predicated on the amount of emitted greenhouse gases and the sensitivity of earth’s surface temperature to changes in their concentrations. Here we take a look at the emissions component.

The U.N. currently entertains four emissions scenarios, all expressed as the change in downwelling radiation (in watts/meter-sq, nominal year 2100) towards the surface that results from an increase in the atmospheric concentration of certain greenhouse gases. They are called “representative concentration pathways,” or RCPs.

As can be seen in Figure 1, there are four, given as 2.6, 4.5, 6(.0) and 8.5. The ranges of associated warming for over 1000 total scenarios are given on the right axis.

Figure 1.  Approximately 1000 scenario runs for four RCPs. From Fuss et al., 2014.

Figure 1. Approximately 1000 scenario runs for four RCPs. From Fuss et al., 2014.

Greener, Not Browner

A recent Science paper by J-F. Busteri and 30 named coauthors assisted by 239 volunteers found, looking at global drylands (about 40% of land areas fall into this category), that we had undercounted global forest cover by a whopping “at least 9%.” 239 people were required to examine over 210,000 0.5 hectare (1.2 acre) sample plots in GoogleEarth, and classify the cover as open or forested. Here’s the resultant cool map:

How Does One Justify One of the Most Expensive Regulations in American History?

In an effort to justify its massive global warming regulations, the Obama Administration had to estimate how much global warming would cost, and therefore how much money their plans would “save.” This is called the “social cost of carbon” (SCC). Calculating the SCC requires knowledge of how much it will warm as well as the net effects of that warming. Needless to say, the more it warms, the more it costs, justifying the greatest regulations. 

Obviously this is a gargantuan task requiring expertise a large number of agencies and cabinet departments. Consequently, the Administration cobbled a large “Interagency Working Group” (IWG) that ran three combination climate and economic models. A reliable cost estimate requires a confident understanding of both future climate and economic conditions. The Obama Administration decided it could calculate this to the year 2300, a complete fantasy when it comes to the way the world produces and consumes energy. It’s an easy demonstration that we have a hard enough time getting the next 15 years right, let alone the next 300.

Consider the case of domestic natural gas. In 2001, everyone knew that we were running out. A person who opined that we actually would soon be able to exploit hundreds of years’ worth, simply by smashing rocks underlying vast areas of the country, would have been laughed out of polite company. But the previous Administration thought it could tell us the energy technology of 2300. As a thought experiment, could anyone in 1717 foresee cars (maybe), nuclear fission (nope), or the internet (never)? 

On the climate side alone, there’s obviously some range of expected warming, often expressed as the probabilities surrounding some “equilibrium climate sensitivity” (ECS), or the mean amount of warming ultimately predicted for a doubling of atmospheric carbon dioxide. In the UN’s last (2013) climate compendium, their 100+ computer runs calculated an average of 3.2°C (5.8°F). A rough rule of thumb would be that this is also an estimate of the total temperature change predicted from the late 20th century to the year 2100.

You Ought to Have a Look: On Fixing Science

You Ought to Have a Look is a regular feature from the Center for the Study of Science. While this section will feature all of the areas of interest that we are emphasizing, the prominence of the climate issue is driving a tremendous amount of web traffic. Here we post a few of the best in recent days, along with our color commentary.

This week we focus on an in-depth article in Slate authored by Sam Apple that profiles John Arnold, “one of the least known billionaires in the U.S.” Turns out Mr. Arnold is very interested in “fixing” science. His foundation, the Arnold Foundation, has provided a good deal of funding to various research efforts across the country and across disciplines aimed at investigating how the scientific incentive structure results in biased (aka “bad”) science. His foundation has supported several high-profile science-finding replication efforts, such as those being run by Stanford’s John Ioannidis (whose work we are very fond of) and University of Virginia’s Brian Nosek who runs a venture called the “Reproducibility Project” (and who pioneered the badge system of rewards for open science that we previously discussed). The Arnold Foundation has also provided support for the re-examining of nutritional science, an effort lead by Gary Taubes (also a favorite of ours), as well as investigations into the scientific review process behind the U.S. government’s dietary guidelines, spearheaded by journalist Nina Teicholz.

Apple writes that:

In my conversations with Arnold and his grantees, the word incentives seems to come up more than any other. The problem, they claim, isn’t that scientists don’t want to do the right thing. On the contrary, Arnold says he believes that most researchers go into their work with the best of intentions, only to be led astray by a system that rewards the wrong behaviors.

This is something that we, too, repeatedly highlight at the Center for the Study of Science and investigating its impact is what we are built around.

Apple continues:

[S]cience, itself, through its systems of publication, funding, and advancement—had become biased toward generating a certain kind of finding: novel, attention grabbing, but ultimately unreliable…

“As a general rule, the incentives related to quantitative research are very different in the social sciences and in financial practice,” says James Owen Weatherall, author of The Physics of Wall Street. “In the sciences, one is mostly incentivized to publish journal articles, and especially to publish the sorts of attention-grabbing and controversial articles that get widely cited and picked up by the popular media. The articles have to appear methodologically sound, but this is generally a lower standard than being completely convincing. In finance, meanwhile, at least when one is trading with one’s own money, there are strong incentives to work to that stronger standard. One is literally betting on one’s research.”

A CO2-Induced Increase in Subtropical North Atlantic Coccolithophore Abundance

Coccolithophores are calcifying phytoplankton that comprise the base of marine food webs all across the world ocean. They play an important role in the cycling of carbon into the deep ocean and act as a feedback to climate change. Anything that alters their function or abundance, therefore, could have significant impacts on marine ecosystems and global climate. Thus, it is no surprise that scientists are interested in how coccolithophores will respond to future changes in atmospheric CO2 and climate. And in this regard, Krumhardt et al. (2016) say there has been “much speculation [that has] inspired numerous laboratory and mesocosm experiments, but how they are currently responding in situ is less well documented.” Working to provide just such an in situ analysis, the team of four researchers thus set out to analyze coccolithophore abundance in the subtropical North Atlantic over the period 1990 to 2014.

To accomplish their objective, Krumhardt et al. used coccolithophore pigment data collected at the Bermuda Atlantic Time-series Study (BATS) site (located at 31.7°N, 64.2°W in the Sargasso Sea) in conjunction with satellite estimates of surface chlorophyll and particulate inorganic carbon as a proxy measure of coccolithophore abundance. Results of their analysis revealed that “coccolithophore populations in the North Atlantic subtropical gyre have been increasing significantly over the past two decades. More specifically, they note there was a 37 percent increase in euphotic zone-integrated (integrated from 140 m depth) in coccolithophore pigment abundance at BATS and a larger 68 percent increase in the upper 30 m of the water column (see figure below). Such findings, in the words of the authors, add to those of a growing number of studies showing that coccolithophores in the North Atlantic “are increasing in abundance and are likely stimulated by additional carbon from anthropogenic sources.”

Elevated CO2 Stimulates the Growth of Papaya

Papayas are spherical or pear-shaped fruits known for their delicious taste and sunlit color of the tropics. Upon his arrival to the New World, Christopher Columbus apparently could not get enough of this exotic fruit, reportedly referring to it as the “the fruit of angels.” And the fruit of angels it may indeed be, as modern science has confirmed its value as a rich source of important vitamins, antioxidants and other health-promoting substances to the consumer.

Elevated CO2: A Key Driver of Global Greening Observations

Despite a constant barrage of stories portraying rising atmospheric carbon dioxide (CO2) as a danger and threat to the planet, more and more scientific evidence is accruing showing that the opposite is true. The latest is in a paper recently published in the journal Scientific Reports, where Lu et al. (2016) investigated the role of atmospheric CO2 in causing the satellite-observed vegetative greening of the planet that has been observed since their launch in 1978.

It has long been known that rising CO2 boosts plant productivity and growth, and it is equally well-established that increased levels of atmospheric CO2 reduce plant water needs/requirements, thereby improving their water use efficiency. In consequence of these two benefits, Lu et al. hypothesized that rising atmospheric CO2 is playing a significant role in the observed greening, especially in moisture-limited areas where soil water content is a limiting factor in vegetative growth and function. To test their hypothesis, the three scientists conducted a meta-analysis that included 1705 field measurements from 21 distinct sites from which they evaluated the effects of atmospheric CO2 enrichment on soil water content in both dryland and non-dryland systems.

A Century of Precipitation Trends in Victoria, Australia

In the debate over CO2-induced global warming, projected impacts on various weather and climate-related phenomena can only be adjudicated with observed data. Even before the specter of dreaded global warming arose, scientists studied historical databases looking for secular changes or stability. With the advent of general circulation climate models, using historical data, scientists can determine whether any observed changes are consistent with the predictions of these models as atmospheric carbon dioxide increases.

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