That's right, some lab coated geeks figured out how to con some enzymes and other quasi living beings into reforming Co2 into C4 in their guts. From the article:
Some of her collaborators managed to isolate and alter nitrogenase to use the most oxidized form of carbon, carbon dioxide, as its starting material and produce the most reduced form of carbon — methane.
“We wanted to see if we could get an actual living organism to do this conversion,” Harwood said.
On the other hand, the new engineered nitrogenase in R. palustris converts carbon dioxide into methane on its own in a single step, simplifying the process. And since it occurs in a living organism, the reaction takes place at ambient temperatures, reducing the energy required to produce a biofuel.
We are confused. Should we be worried about a world where Co2 becomes scarce as the human engineered chimera nitrogenase in R. palustris converts all available Co2 to C4? Or should we rejoice that global warming is no longer an issue?