Two green energy items popped up on my news radar today, both by Wired Science writer Alexis Madrigal. First is news out of California of a new computer model created by the Dave Rutledge, chair of Caltech's engineering and applied sciences division, that shows the world's coal reserves are way lower than we thought. Also out of California is a new simulation showing that the energy grid is capable of taking a much larger load of renewable energy than previously calculated.

First off, the coal.

Rutledge's model shows that humans will pull up a total of 662 billions of tons of coal, including everything we've pulled out of the ground so far. The previous estimate have shown 850-950 billion tons of coal still left in the ground. That's quite a gap.

He got his numbers by looking at the historical peaks and valleys of fossil fuel use like British coal at the beginning of the century and America's peak oil hit in the 70's and factoring in production for entire regions.

If his model is anywhere close to being true, it could mean humanity has a fighting chance in the war on coal, if only due to our inability to pull enough of it out of the ground to completely shoot ourselves in the feet. At those numbers the concentration of CO2 in the environment would hit somewhere around 460 parts per million. We're at 380 ppm now, Al Gore wants us around 350.

460 ppm is still too high, but that's the max ceiling we'd hit if we did nothing but burn up the couple hundred billions tons of coal we'd have left. That's a whole magnitude less than if we have 900 billions of tons of coal

If we did what was good for us we'd get into action weaning ourselves off of coal. No matter which set of numbers you choose to believe, we're screwed no matter which path we go down. If coal reserves are much lower than previously thought, we're in for a painful reminder of the reliance our world has on cheap coal as we see the price of everything go up as the availability goes down. On the flip side if we have as much coal as some think, we'll destroy our climate by burning it all up.

The only solution is to develop alternative energy sources and get off of coal.

Which brings us to the other news item that caught my attention today- another long held number potentially fell as a new computer simulation (PDF) presented at the American Geophysical Union meeting in California shows that the state's power grid could be capable of handling more than three times as much renewable energy as thought.

The nation's power grid is an antiquated system that hasn't changed much in principle since George Westinghouse AC transmission system beat out Edison Direct Current (DC). It's been generally accepted that the grid wouldn't be able to handle getting more than 20% of it's total power load from renewable energy sources without widespread and costly upgrades.

Like the coal numbers, if these projections are true it will mean big green changes for the better. If we don't need to upgrade the power grid for the first 70% of the transition to 100% renewable energy it means things will scale up to that point a lot quicker than if we had to start improving it at 20%. It puts the excuse of "it's too costly to upgrade the grid" right off the table. If these numbers are true and assuming we see some kind of cap and trade system sometime soon, it will be more costly NOT to switch to renewable energy.

Links [Wired: Power Grid] & [Wired: Coal Reserves]

The opinions expressed by MNN Bloggers and those providing comments are theirs alone, and do not reflect the opinions of While we have reviewed their content to make sure it complies with our Terms and Conditions, MNN is not responsible for the accuracy of any of their information.