Tag: climate change

You Ought to Have a Look: How Climate Alarm Becomes a Self-promulgating Collective Belief

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.

There was an interesting stream of articles this week that, when strung together, provides a pretty good idea as to how the scientific literature on climate change can (and have) become biased in a hurry.

First up, consider this provocative article by Vladimir Jankovic and David Schultz of University of Manchester titled “Atmosfear: Communicating the effects of climate change on extreme weather.” They formalize the idea that climate change communication has become dominated by trying to scare folks into acceptance (and thus compliance with action). The abstract is compelling:

The potential and serious effects of anthropogenic climate change are often communicated through the soundbite that anthropogenic climate change will produce more extreme weather. This soundbite has become popular with scientists and the media to get the public and governments to act against further increases in global temperature and their associated effects through the communication of scary scenarios, what we term “atmosfear.” Underlying atmosfear’s appeal, however, are four premises. First, atmosfear reduces the complexity of climate change to an identifiable target in the form of anthropogenically forced weather extremes. Second, anthropogenically driven weather extremes mandate a responsibility to act to protect the planet and society from harmful and increased risk. Third, achieving these ethical goals is predicated on emissions policies. Fourth, the end-result of these policies—a non-anthropogenic climate—is assumed to be more benign than an anthropogenically influenced one. Atmosfear oversimplifies and misstates the true state of the science and policy concerns in three ways. First, weather extremes are only one of the predicted effects of climate change and are best addressed by measures other than emission policies. Second, a pre-industrial climate may remain a policy goal, but is unachievable in reality. Third, the damages caused by any anthropogenically driven extremes may be overshadowed by the damages caused by increased exposure and vulnerability to the future risk. In reality, recent increases in damages and losses due to extreme weather events are due to societal factors. Thus, invoking atmosfear through such approaches as attribution science is not an effective means of either stimulating or legitimizing climate policies.

You Ought to Have a Look: Natural Climate Variability

You Ought to Have a Look is a feature from the Center for the Study of Science posted by Patrick J. Michaels and Paul C. (“Chip”) Knappenberger. 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.

We’ve got a lot cover this week, so let’s get right to it.

On the science front, we want to highlight two new papers that both suggest that attributing heavy precipitation events in the United States to human-caused climate change is a fool’s errand (not that there aren’t plenty of fools running around out there). This is a timely topic to explore with the big rains in Louisiana over the weekend leading the news coverage.

One paper by a research team from the University of Iowa found that “the stronger storms are not getting stronger” and that there has not been any change in the seasonality of heavy rainfall events by examining trends in the magnitude, frequency, and seasonality of heavy rainfall events in the United States. They did report that the frequency of heavy rain events was increasing across much of the United States, with the exception of the Northwest. As to the reason behind the observed patterns, the authors write “[o]ur findings indicate that the climate variability of both the Atlantic and Pacific Oceans can exert a large control on the precipitation frequency and magnitude over the contiguous USA.”

The other paper, from a research team led by NOAA/GFDL’s Karin van der Wiel, examined climate model projections and observed trends in heavy precipitation events across the United States and concludes:

Finally, the observed record and historical model experiments were used to investigate changes in the recent past. In part because of large intrinsic variability, no evidence was found for changes in extreme precipitation attributable to climate change in the available observed record.

Pretty emphatic and straightforward summary.

So, the next time you read that such and such extreme precipitation event was made worse by global warming, you’ll know that there is precious little actual science to back that up.

Six Decades of Temperature and Precipitation in Kentucky

Air temperature and precipitation, in the words of Chattopadhyay and Edwards (2016), are “two of the most important variables in the fields of climate sciences and hydrology.” Understanding how and why they change has long been the subject of research, and reliable detection and characterization of trends in these variables is necessary, especially at the scale of a political decision-making entity such as a state. Chattopadhyay and Edwards evaluated trends in precipitation and air temperature for the Commonwealth of Kentucky in the hopes that their analysis would “serve as a necessary input to forecasting, decision-making and planning processes to mitigate any adverse consequences of changing climate.”

Data used in their study originated from the National Oceanic and Atmospheric Administration and consisted of time series of daily precipitation and maximum and minimum air temperatures for each Kentucky county. The two researchers focused on the 61-year period from 1950-2010 to maximize standardization among stations and to ensure acceptable record length. In all, a total of 84 stations met their initial criteria. Next, Chattopadhyay and Edwards subjected the individual station records to a series of statistical analyses to test for homogeneity, which reduced the number of stations analyzed for precipitation and temperature trends to 60 and 42, respectively. Thereafter, these remaining station records were subjected to non-parametric Mann-Kendall testing to assess the presence of significant trends and the Theil-Sen approach to quantify the significance of any linear trends in the time series. What did these procedures reveal?

For precipitation, Chattopadhyay and Edwards report only two of the 60 stations exhibited a significant trend in precipitation, leading the two University of Kentucky researchers to state “the findings clearly indicate that, according to the dataset and methods used in this study, annual rainfall depths in Kentucky generally exhibit no statistically significant trends with respect to time.” With respect to temperature, a similar result was found. Only three of the 42 stations examined had a significant trend. Once again, Chattopadhyay and Edwards conclude the data analyzed in their study “indicate that, broadly speaking, mean annual temperatures in Kentucky have not demonstrated a statistically significant trend with regard to time.”

Given such findings, it would seem that the vast bulk of anthropogenic CO2 emissions that have been emitted into the atmosphere since 1950 have had little impact on Kentucky temperature and precipitation, because there have been no systematic trends in either variable.

 

Reference

Chattopadhyay, S. and Edwards, D.R. 2016. Long-term trend analysis of precipitation and air temperature for Kentucky, United States. Climate 4: 10; doi:10.3390/cli4010010.

You Ought to Have a Look: Platform Planks on Energy and the Environment

You Ought to Have a Look is a feature from the Center for the Study of Science posted by Patrick J. Michaels and Paul C. (“Chip”) Knappenberger.  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.

With the end of Convention season mercifully upon us, we thought we ought to have a look at what the party platforms have to say about energy and the environment, with an eye on climate change policies in particular.

We’ll start out with the Democratic Party Platform.

The Democrats are of the mind that human-caused climate change is one of the major problems facing the country/world today, describing it as “an urgent threat and a defining challenge of our time.”

It’s unclear that the voters feel that way… although part of the Democrats strategy for this election seems to be to try to persuade them otherwise.

The Democratic platform is chock full of government actions that promise to initiate, broaden and extend the current set of rules, regulation, and orders seeking to reduce our emissions of carbon dioxide (and other greenhouse gases), largely by way of lessening (on the way to eliminating) our reliance on fossil fuels as our primary source of energy production. This collection of promised federal actions is large both in scope and number and includes everything from pursuing a carbon tax

You Ought to Have a Look: 2016’s Temperature Evolution, a Retraction of a Fracking Cancer Warning, and a Look at Antarctic Sea Ice Trends

You Ought to Have a Look is a feature from the Center for the Study of Science posted by Patrick J. Michaels and Paul C. (“Chip”) Knappenberger.  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.

At the top of our list of things you ought to have a look at this week is a pair of blog posts by Dr. Roy Spencer updating the recent post-El Niño evolution of the satellite-observed temperature record of the earth’s lower atmosphere. In Roy’s first post, he updates the satellite record through June 2016, noting the big drop in temperatures as the effect of the recent big El Niño wanes. The take home figure looks like this:

Figure 1. Global average temperature of the lower atmosphere as derived and compiled by researchers at the University of Alabama at Huntsville, January 1979 through June 2016.

Figure 1. Global average temperature of the lower atmosphere as derived and compiled by researchers at the University of Alabama at Huntsville, January 1979 through June 2016.

Roy notes that the “2-month temperature fall of -0.37 deg. C, which is the second largest in the 37+ year satellite record.”

In a follow-on post, Roy looks to see what the prospects are for the 2016 annual temperatures being the highest in the 38-year satellite temperature history. In late June, Roy had concluded that is “2016 Will Likely See Record Global Warmth in Satellite Data.” But with the big drop in June temperatures, he is now reconsidering, writing that his previous prediction “looks…well…premature.” 

Be sure to check out all Roy’s analysis and keep tuning in to see how the year’s temperatures are progressing. We surely will be.

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.

Papaya production has increased significantly over the past few years to the point that it is now ranked fourth in total tropical fruit production after bananas, oranges and mango. It is an important export in many developing countries and provides a livelihood for thousands of people. It should come as no surprise, therefore, that scientists have become interested in how this important food crop might respond to increasing levels of atmospheric CO2 that are predicted for the future.

Such interest was the focus of a recent paper published in the scientific journal Scientia Horticulturae by Cruz et al. (2016). Therein, the team of five researchers examined “the effect of the elevated CO2 levels and its interaction with Nitrogen (N) on the growth, gas exchange, and N use efficiency (NUE) of papaya seedlings,” as they note there are no publications examining such for this species to date. To accomplish their objective, Cruz et al. grew Tainung #1 F1 Hybrid papaya seeds in 3.5 L plastic pots in a climate-controlled greenhouse at the USDA-ARS Crops Research Laboratory in Fort Collins, Colorado under two different CO2 concentrations (390 or 750 parts per million) and two separate N levels (8 mM NO3- or 3 mM NO3-). CO2 fumigation was performed for only 12 hours per day (during the day, 06:00 h to 18:00 h) and N treatments were applied to the pots weekly as a nutrient solution to reach the desired N levels. The experiment concluded 62 days after treatment initiation.

In discussing their findings, Cruz et al. report that compared to ambient levels of CO2, elevated CO2 increased photosynthesis by 24 and 31 percent in the low and high N treatments, respectively. Plant height, stem diameter and leaf area in the high N treatment were also enhanced by 15.4, 14.0 and 26.8 percent, respectively, and by similar amounts for the height and stem diameter in the low N treatment. Elevated CO2 also increased the biomass of leaf, stem plus petiole, and root dry mass of papaya plants regardless of N treatment, leading to total dry mass enhancements of 56.6 percent in the high N treatments and 64.1 percent in the low N treatments (see figure below).

Figure 1. Total dry mass of papaya plants grown in controlled chambers at two different CO2 concentrations (High and Low; 750 and 390 ppm) and two different N treatments (High and Low; 8 mM NO3- or 3 mM NO3-). Adapted from Cruz et al. (2016).

Figure 1. Total dry mass of papaya plants grown in controlled chambers at two different CO2 concentrations (High and Low; 750 and 390 ppm) and two different N treatments (High and Low; 8 mM NO3- or 3 mM NO3-). Adapted from Cruz et al. (2016).

 

Cruz et al. also report that “significant, but minor, differences were observed in total N content (leaf plus stem + petiole plus roots) between plants grown at different CO2 concentrations, but the same N levels.” Consequently, plant Nitrogen Use Efficiency (NUE) – the amount of carbon fixed per N unit – was around 40 percent greater in the CO2-enriched environments, regardless of the N level in the soil.

Commenting on their findings, Cruz et al. write that contrary to some other studies, which have suggested that low N reduces plant responses to increased CO2 levels, they found no such decline. In fact, their data indicate that elevated CO2 “alleviated the effect of low N on dry matter accumulation in papaya,” which they surmised is at least partially explained by a larger leaf area and higher rate of photosynthesis per leaf area unit observed under elevated CO2.

In light of all of the above, Cruz et al. conclude that “an increase in the atmospheric CO2 concentration [is] beneficial for dry mass production of papaya and alleviate[s] the negative effects of N reduction in the substrate on papaya growth.” Thus, in the future, those who cultivate this fruit of angels should find an angel in the ongoing rise in atmospheric CO2.

 

Reference

Cruz, J.L., Alves, A.A.C., LeCain, D.R., Ellis, D.D. and Morgan, J.A. 2016. Interactive effects between nitrogen fertilization and elevated CO2 on growth and gas exchange of papaya seedlings. Scientia Horticulturae 202: 32-40.

What Goes Up…

Must come down. Of course, we’re referring to lower atmospheric temperatures measured by satellites.

For months we have been saying that, once they started dropping, the satellite temperatures—our only truly global measure—were going to go down with a vengeance, which is what usually happens after a strong El Niño event spikes a fever. El Niño is a dramatic slowdown (or even a reversal) in the trade winds that diverge surface water away from the South American coast, “upwelling” much colder subsurface waters. When that stops, global temperatures rocket upwards, but that also builds up more and more cold water to be unleashed when the trade winds resume.

If the 1998 El Niño is any guide, global temperatures are going to be back in (or near) “pause” mode by by the turn of the year.

If the 1998 El Niño is any guide, global temperatures are going to be back in (or near) “pause” mode by by the turn of the year.

According to University of Alabama-Huntsville’s Roy Spencer, who publishes the satellite data, the drop in the last two months was the second-largest in the entire record, missing the record by only 0.01⁰C. That record was set—not surprisingly—in the decline after the slightly bigger 1997-8 El Niño. In the tropics, where El Niño is most expressed, the drop was the largest in the entire 37-year record. 

For what it’s worth, no one knows what the ultimate cause of an El Niño is. While they are the largest secular oscillation in global surface temperatures,  computer models for global warming can’t simulate them realistically, and even short-term (year in advance) forecasting models are pretty lousy when it comes to initiating one.

Despite the recent peak, the satellite data never lost the “pause” that began in 1996. As far as the surface temperatures go, recent adjustments that “disappeared” that pause are looking more and more suspect as other independent data (like the satellites) do not corroborate them. Stay tuned for more, as we have just submitted an article on this problem.