UGO BARDI

Coal seemed to have peaked in 1990, but it was an illusion. The growth of coal production during the first decade of the 21st century has been impressive; never seen before in history. So, King Coal is coming back and he may soon reclaim the title of ruler of the energy world that it had lost to crude oil in the 1960s.

The propaganda technique of the repeated lie has been applied obsessively, against the "hockey stick," the reconstruction of past temperatures on which Michael Mann and coworkers had been working from the 1990s.

It is rare in the history of science that a single piece of experimental evidence has been the object of so many attempts of demolition. Yet, all the serious reviews of the original data have basically confirmed the initial results. Being unsuccessful in demolishing the science, the attacks have moved against the scientist, Michael Mann himself, who has been subjected to an unbelievable denigration campaign, defamed, insulted, and even physically threatened.

With the publication of a prominent article on "Nature" in January 2012, the concept of "Peak Oil" has made another step forward in the debate on resource depletion. This article has made me rethink of the past ten years of work that I did as a member of ASPO, the association for the study of peak oil. Were we right with our prediction of impending peak oil? In a sense, yes, but the crystal ball is always foggy and it cannot be otherwise. The ASPO predictions were basically right but, as all predictions, they were approximate.

Methane hydrates are a true climate bomb that could go off by itself as the result of a relatively small trigger in the form of a global warming. Sufficient warming would cause the decomposition of some hydrates to release methane to the atmosphere. This methane would create more warming and that would generate more decomposition of the hydrates.

The effects of the rapid release of so much methane would be devastating: an abrupt climate change that could bring a true planetary catastrophe.

Scientists seem to be discovering that they can't stick to the old ways any longer. After all, the quality of a paper doesn't reside on the seal of a commercial editor, it is guaranteed by the peer reviewing process. And scientists are doing peer reviewing, not editors. So, scientists tend to publish more and more in "open access journals", which just didn't exist up to not long ago. There is now an "open science movement", and a movement to boycott Elsevier, singled out among the many scientific editors as an especially bad one.

Occasionally, the troubled story of Alfred Wegener's theory has been perversely appropriated by climate deniers to claim that they are discriminated by the scientific establishment. But that only shows that climate deniers don't understand how science works.

The latest scientific revolution is in planetary science. It seems almost unbelievable that just some decades ago people were still debating on whether extrasolar planets actually existed. Today, we are discovering so many of them that it is now believed that almost every star in the galaxy has planets.

The new science of planetary systems gives us a pretty clear view of how we can destroy our civilization by upsetting the delicate balance of the factors that keep our planet alive and friendly to us. We can do it in more than one way, but the most effective one is to continue to emit greenhouse gases in the atmosphere. So, once you have looked at the stars, come back to Earth and start doing something because we are all in trouble.

If you have always been thinking that biofuels are not a good idea, this book by Mario Giampietro and Kozo Mayumi will tell you exactly why in their book, The Biofuel Delusion.

The return of interest in "The Limits to Growth" continues. After decades of ridicule and insults, the value of the 1972 study and of its sequels is more and more recognized. The latest item in the series of revisitations is an article published by Debora McKenzie in the latest New Scientist magazine.

The story of the Empress Galla Placidia deals with such things as system dynamics, the fall of empires, resource depletion, controlling complex systems and, yes, also a little about Christmas.

Her story seems like the plot of an adventure movie. She started as a princess, then she was prisoner of the Goths, then she became their Queen, then she was again their prisoner.

In the 5th century, when she came to power, the Roman Empire had been running out of reactants. It had been growing on the profits made from military campaigns but, at some point around the 2nd century, it had reached its limits. With no more easy conquests in sight, the Empire had to live on its own resources and it never really learned how to do that.

During the 5th century, what an emperor (or empress) could have done was to give to the events just a little push in the right direction. Don't fight the change, ease it. It is the way of pushing the levers in the right direction. Could Placidia have done just that? Incredibly, perhaps she did.