Comments by "Tony Wilson" (@tonywilson4713) on "PBS Terra" channel.

  1. This is a great factual report, BUT it needs a follow up on "How to make Tree Planting Work" because we have to make it work. I'm an aerospace engineer and as an under graduate we once had a guest lecturer from NASA talk to us about Terraforming Mars. He broke our hearts with "Sorry but its impossible!" and then explained why. He introduced us to 2 subjects that I now call "Planetary Mechanics" and "Planetary Dynamics". Planetary Mechanics is when you just calculate the basics of what's needed. Planetary Dynamics is how you make it all work and includes things like water, oxygen and nitrogen cycles. When you look at Mars and ask something like how much air would we need to cover mars in a 1km thick layer of Earth Standard Air. It turns out to be 178 Trillion tons. So even before you start asking lots of other questions you have to ask where are you going to get 178 Trillion tons of air? Now applying that to the Earth and our problem of having too much Carbon Dioxide. If you do a simple estimate the 1st kilometer above the Earths surface is approximately 500 Million Cubic Kilometers of air and we need to reduce the CO2 level by about 30% (415ppm down to under 300ppm). The basic questions form that are: 1) How do you process 1/2 a billion cubic kilometers of air to extract slightly more than 1/4 of less than 1% of that air? 2) How much energy is it going to take to build all the hardware needed and then power that hardware? Let me introduce you to the cheapest carbon extraction and sequestration pump there is - A TREE. Trees are low maintenance solar powered carbon extraction and sequestration pumps. The problem is the size of the task because we need every human on the planet to plant or have planted in their name 1,000 trees. Yes 8 Billion people need to plant about 8 Trillion trees and then look after them and let them clean up the mess we have made. To make it work as this video says we need to THINK and plant the right trees in the right places for the right reasons. So that a reasonable percentage of them grow to maturity and suck out the excess carbon dioxide in the atmosphere. It can't just be endless groves of the same stuff. It has to have bio diversity.
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