Know Climate Change Science?

Give yourself an honorary point if you picked carbon dioxide, as CO2 is the most common greenhouse gas in terms of the warming we're now experiencing. However in terms of all contributing factors to the greenhouse effect, water vapor contributes 36-72%. But since we can control CO2 emissions, reducing these should be in the first line of attack.

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Though not a gas, black carbon contributes up to 25% of observed global warming. Its main sources are from burning organic matter (inefficient biomass cookstoves...) and from fossil fuels. When it falls in snowy areas like the Arctic and Himalayas it accelerates melting by lowering reflectivity. It also traps heat in the atmosphere. The good news is that it falls from the atmosphere in a matter of weeks once its sources are removed.

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Though estimates vary, the upper range of greenhouse gas emissions (from the Council on Foreign Relations) from deforestation place them at about 30 percent. More than the global transportation sector. Without tacking global deforestation, we cannot effectively prevent catastrophic climate change.

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In the United States, the EPA says that transportation accounts for 29% of all greenhouse gas emissions and 47% of increases in emissions since 1990. It's also the single largest source of CO2 -- the most prevalent greenhouse gas (apart from water vapor, which we really can't do that much about, remember...)

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REDD is an acronym referring to a UN program which aims to prevent deforestation and forest degradation by (very basically) making it more profitable for nations and forest owners to keep forests standing than converting them to plantations or chopping them down for lumber.

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There are a lot of variables involved here, but conservative estimates say that at minimum by 2100 there will be 50cm of sea level rise, with 1 meter more likely. Other estimates say that at least 2 meters is assured, it's just a question of how fast that will happen.

More: Two Meter Sea Level Rise Now Inevitable - But How Fast Will It Happen?

Permafrost melting is something to be seriously concerned about. Though there have been reports saying that it's unlikely we'll see a rapid release of methane, considering its global warming potential, any increase really isn't so good. Not only that, there's evidence that permafrost contains twice as much methane as we once thought. And, that only 10% of it melting could push us past a climate tipping point, past which it will be near impossible to stabilize the climate to something like we've grown used to.

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