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from the we-used-to-wish-for-warmer-weather dept.
Ocean temperatures hit record high as rate of heating accelerates:
The heat in the world's oceans reached a new record level in 2019, showing "irrefutable and accelerating" heating of the planet.
The world's oceans are the clearest measure of the climate emergency because they absorb more than 90% of the heat trapped by the greenhouse gases emitted by fossil fuel burning, forest destruction and other human activities.
The new analysis shows the past five years are the top five warmest years recorded in the ocean and the past 10 years are also the top 10 years on record. The amount of heat being added to the oceans is equivalent to every person on the planet running 100 microwave ovens all day and all night.
[...]"We found that 2019 was not only the warmest year on record, it displayed the largest single-year increase of the entire decade, a sobering reminder that human-caused heating of our planet continues unabated," said Prof Michael Mann, at Penn State University, US, and another team member.
Journal Reference:
Cheng, L., Abraham, J., Zhu, J. et al. Ocean Temperatures Hit Record High as Rate of Heating Accelerates Adv. Atmos. Sci. (2020) 37: 137. https://doi.org/10.1007/s00376-020-9283-7
(Score: 2) by c0lo on Wednesday January 15 2020, @08:31AM (2 children)
Think a bit, tacking works on sailing due to the interaction of the boat with the water; further, changing the sail orientation is still a thing that requires energy expenditure.
Maintaining position in the void of the space (no water resistance there) will require more energy than what you can capture from the Sun.
- If you don't interact with the photon, your sails stays where it is, but failed your "shading Earth" mission.
- If you absorb a photon, you get a kick from its momentum towards Earth - and there's no "water" your sail can push against to "stay in place"; on the plus side, you may use the absorbed energy to reorient the sail, but not to compensate the kick.
- If you reflect a photon, the kick you incur is gonna vary from "double the absorption kick" (if you reflect it back on the same direction but opposite sense) to almost zero (if you deflect it with just an-ant-boobs-ever-vanishing epsilon). In the first case, the "balancing" will result in the emission of more-than-two-photons-of-the-same-energy-just not directed at Earth. In the second case, your sail is gonna need to be humongous to offer a cross-section able to shade the entire Earth - imagine the energy consumption requires to tack your solar sail in the other direction to balance your position.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Wednesday January 15 2020, @03:45PM
The L1 point is on top of a "gravitational hill". You just put the sail slightly on the sunward side so that the photonic thrust matches and balances the downward drift. Yes, you are still going to need station-keeping thrusters, but the better your navigation the more you can balance things out and reduce their use.
Or if you use gyros to tilt it, you could eliminate the thrusters entirely. Reflect the light at 170 degrees instead of 180 and you have a small thrust that can take you wherever you want. Niven said it best in the integral trees: East takes you Out, Out takes you West, West takes you In, In takes you East. North and South bring you back.
(Score: 0) by Anonymous Coward on Wednesday January 15 2020, @05:29PM
Then position it just beyond the Lagrange point where the sun's gravity exactly offsets the light pressure.