A highlight of recent research supporting the climate realist perspective #8

I have come across four 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 of blog posts.

First is Fragmented patterns of flood change across the United States (press release here), published in Geophysical Research Letters. It argues that much of the United States has experienced no change in floods, and that no countrywide trend is observable. This is great news, since according to the paper, a climate change influence in flooding in the United States as a whole, at least currently, is not apparent. This flies in the face of many alarmist statements, such as that the effects of climate change on floods in the United States are already observable. However, this paper’s results are corroborated by multiple independent studies finding little variation of late in the hydrological cycle, despite the ongoing, partially human-induced global warming.

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Changes in flood patterns across the United States over the past 75 years. Note the lack of cohesive, country-wide change, at least in one direction. From Archfield et al. 2016.

Second is Modification of land-atmosphere interactions by CO2 effects: implications for summer dryness and heatwave amplitude, published in Geophysical Research Letters. It argues, similarly to another recent paper, that beneficial effects of rising CO2 on plants, such as increased leaf area and water use efficiency, will help mitigate projected increases in heat wave and drought impacts. This is also great news, and further lends credence to the idea that the beneficial effects of rising CO2 will at least partially offset some of the negative effects.

Third is Assessing recent trends in high-latitude Southern Hemisphere surface climate (press release here), published in Nature Climate Change. It argues that recent trends in high-latitude Southern Hemisphere climate, such as sea-ice extent, temperature, and sea level pressure, (with the exception of the Southern Annular Mode) are within the bounds of the past 200 years and can be explained by natural variability. This result is especially fascinating, since humans have spewed so much CO2 and other GHGs into the atmosphere and yet natural variability can still overwhelm that signal. This thus implies that climate sensitivity may be on the low end of the IPCC’s range: 1.5 to 4.5 degrees Celsius for a doubling of CO2 in the atmosphere.

Fourth is Decrease in climatic conditions favouring floods in the south-east of Belgium over 1959–2010 using the regional climate model MAR, published in International Journal of Climatology. It argues that warming in Belgium actually decreased the chances for conditions favorable for floods to develop. This result is also fascinating, and again contradicts the simplistic view that climate change will simply make virtually climatic extremes worse everywhere.

As I noted before, evidence accumulates seemingly every passing week supporting the climate realist perspective. One can only hope that such papers will get more recognition than they currently do.

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Impact of the ~ 2400 yr solar cycle on climate and human societies

Here’s an excellent essay posted at Climate Etc., an excellent, climate realist blog run by Dr. Judith Curry, a climate scientist, climate realist, and professor at Georgia Tech, by a guest author named Javier. The article has a great summary of the solar effect on climate, more particularly the effect of the ~2400-year Bray solar cycle on climate, and I thought it so good I should share it with you. (Javier and I share many similar views on the effects of solar activity variations on climate and their implications for current climate debates.)

Climate Etc.

*by Javier

The role of solar variability on climate change, despite having a very long scientific tradition, is currently downplayed as a climatic factor within the most popular hypothesis for climate change.

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A highlight of recent research supporting the climate realist perspective #7

I have come across a scientific paper published recently, which supports the climate realist perspective, and thought it of such significance that I should share it here, in my climate realist paper update series.

The paper in question (press release here) has been published in Science Advance. It argues that recent unprecedented tree growth in the Tibetan Plateau is due to CO2 increases. The paper finds that the direct effects of increased CO2 on plant growth, from fertilization, and indirect effects, from melting of permafrost caused by CO2-induced warming, which makes more nutrients and water from the snow available to the trees, work in tandem to increase forest growth and thus defy predictions that climate change will have a negative impact on forests worldwide. This is great news, and the increase in forest growth will also help to remove CO2 from the atmosphere, providing a negative feedback. This work is especially interesting in light of recent papers (press releases here and here) arguing that humans are greening the earth, the former of which, corroborating the results of Silva et al. 2016, finds that the Tibetan Plateau is greening mainly because the indirect effects of CO2 (as opposed to most of the rest of the earth): those effects resulting from CO2-induced warming. And as always, it’s important to remember other beneficial effects (while also considering the negative effects, since some beneficial effects simply offset some negative effects from rising CO2!), be they direct or indirect, of rising CO2 levels, leve such as offsetting much of the negative effects of projected drought increases.

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Rate of tree growth over time. Note the recent, rapid increases. From Silva et al. 2016

A highlight of recent research supporting the climate realist perspective #6

I have come across a scientific paper published recently, which supports the climate realist perspective, and thought it of such significance that I should share it here, in my climate realist paper update series of blog posts.

The paper in question (press release here) has been published in Proceedings of the National Academy of Sciences, and it makes an interesting point regarding droughts and climate change. It argues that the beneficial effects from rising CO2, such as modified plant water usage, can offset much of the negative effects from droughts caused by rising CO2. Because of rising CO2, plants need less water, keep more of it on land, and thus are less affected by the projected rise in frequency and intensity of droughts, argues Swann et al. 2016. In fact, the paper argues that though 70% of the earth is projected to experience increases in droughts over the 21st century, this number drops to 37% if you include the positive effects of CO2 on plants. This is great news, especially for the places which the paper finds will not be affected by the rise in droughts very much: Central Africa, China, the Middle East, East Asia, and most of Russia. This most certainly supports the climate realist perspective, as do so many other papers, by again showing that at least some of the alarm associated with climate change is not deserved. Furthermore, projected drought and precipitation patterns may not necessarily correspond with observations, as shown by multiple independent studies.

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Changes in global drought patterns since 1950. Note the lack of a strong trend. From Sheffield et al. 2012.