Guest essay by Eric Worrall
Harvard University is planning to conduct an experiment to test the effectiveness of sunlight blocking aerosols dumped into the stratosphere.
Harvard Scientists Begin Experiment To Block Out The Sun
Dec 5, 2018, 12:40pm
A group of Harvard scientists plans to tackle climate change through geoengineering by blocking out the sun. The concept of artificially reflecting sunlight has been around for decades, yet this will be the first real attempt at controlling Earth’s temperature through solar engineering.
The project, called Stratospheric Controlled Perturbation Experiment(SCoPEx), will spend $3 million to test their models by launching a steerable balloon in the southwest US 20 kilometers into the stratosphere. Once the balloon is in place, it will release small particles of calcium carbonate. Plans are in place to begin the launch as early as the spring of 2019.
The basis around this experiment is from studying the effects of large volcanic eruptions on the planet’s temperature. In 1991, Mount Pinatubo in the Philippines erupted spectacularly, releasing 20 million tonnes of sulfur dioxide into the stratosphere. The sulfur dioxide created a blanket around Earth’s stratosphere, cooling the entire planet by 0.5 °C for around a year and a half.
From the description of the experiment;
Stratospheric Controlled Perturbation Experiment (SCoPEx)
SCoPEx is a scientific experiment to advance understanding of stratospheric aerosols that could be relevant to solar geoengineering. It aims to reduce the uncertainty around specific science questions by making quantitative measurements of some of the aerosol microphysics and atmospheric chemistry required for estimating the risks and benefits of solar geoengineering in large atmospheric models. SCoPEx will address questions about how particles interact with one another, with the background stratospheric air, and with solar and infrared radiation. Improved understanding of these processes will help answer applied questions such as, is it possible to find aerosols that can reduce or eliminate ozone loss, without increasing other physical risks?
At the heart of SCoPEx is a propelled scientific balloon that can travel a few meters per second (walking speed) relative to the surrounding air. The propellers serve two functions. First, the propeller wake forms a well mixed volume (roughly 1 km long and 100 meters in diameter) that serves as an experimental ‘beaker’ in which we can add gasses or particles. Second, the propellers allow us to fly the gondola back and forth through the volume to measure the properties of the perturbed air.
The advantage of the SCoPEx propelled balloon is that it allows us to create a small controlled volume of stratospheric air and observe its evolution for (we hope) over 24 hours. Hence the acronym, Stratospheric Controlled Perturbation Experiment. If we used an aircraft instead of a balloon, we would not be able to use such a small perturbed volume nor would we be able to observe it for such long durations.
What is the experiment?
We plan to use a high-altitude balloon to lift an instrument package approximately 20 km into the atmosphere. Once it is in place, a very small amount of material (100 g to 1 kg) will be released to create a perturbed air mass roughly one kilometer long and one hundred meters in diameter. We will then use the same balloon to measure resulting changes in the perturbed air mass including changes in aerosol density, atmospheric chemistry, and light scattering.
Obviously this experiment will not cause any harm – the quantity of material the Harvard Scientists intend to release will not have a significant effect at ground level. What frightens me is the possibility of larger scale experiments, serious attempts to lower global temperature.
From a study published in August;
Estimating global agricultural effects of geoengineering using volcanic eruptions
Published: 08 August 2018
Jonathan Proctor, Solomon Hsiang, Jennifer Burney, Marshall Burke & Wolfram Schlenker
Solar radiation management is increasingly considered to be an option for managing global temperatures, yet the economic effects of ameliorating climatic changes by scattering sunlight back to space remain largely unknown. Although solar radiation management may increase crop yields by reducing heat stress, the effects of concomitant changes in available sunlight have never been empirically estimated. Here we use the volcanic eruptions that inspired modern solar radiation management proposals as natural experiments to provide the first estimates, to our knowledge, of how the stratospheric sulfate aerosols created by the eruptions of El Chichón and Mount Pinatubo altered the quantity and quality of global sunlight, and how these changes in sunlight affected global crop yields. We find that the sunlight-mediated effect of stratospheric sulfate aerosols on yields is negative for both C4 (maize) and C3 (soy, rice and wheat) crops. Applying our yield model to a solar radiation management scenario based on stratospheric sulfate aerosols, we find that projected mid-twenty-first century damages due to scattering sunlight caused by solar radiation management are roughly equal in magnitude to benefits from cooling. This suggests that solar radiation management—if deployed using stratospheric sulfate aerosols similar to those emitted by the volcanic eruptions it seeks to mimic—would, on net, attenuate little of the global agricultural damage from climate change. Our approach could be extended to study the effects of solar radiation management on other global systems, such as human health or ecosystem function.
A serious attempt to block sunlight using stratospheric aerosols could cause global crop failure and famine.
You would think that given the obvious problems nobody would go forward with such an effort. But the green political scientific nexus has a track record of not considering the consequences of their actions.
Back in 2008 lavish biofuel subsidies caused hunger and food riots in poor countries, as subsidised grain purchases drove up the global price of vital agricultural staples.
The ongoing fuel tax protests in France are another example of a serious failure by greens to consider the consequences of their actions. Despite belated French government efforts to retreat from their original provocation, the situation in France is now so unstable the French police union is urging members to join the protests.
Given the horrendous track record of green political irresponsibility, it is reasonable to be concerned about the harm geoengineers and their green political sponsors may cause, if one of their over enthusiastic sunlight blocking experiments goes awry.
via Watts Up With That?
December 8, 2018 at 12:04PM