FROM THE AUTHORS: In the piece we should have more clearly noted that Article 4.1 of the Paris Agreement commits countries to undertake rapid reductions “so as to achieve a balance between anthropogenic emissions by sources and removals of sinks of greenhouse gases in the second half of the century”. As several readers have correctly pointed out, this is technically the same as net-zero, and it is very important that this language was included in this historic agreement, which we fully support. It is important to note that in the long term, natural sinks of CO2 are too slow and small to matter, so the only way of balancing residual CO2 emissions is by artificial CO2 removal, which as we point out is both hard and unproven. Thus the point of our piece is that many people, including many business leaders, investors, media, politicians, and even experts, don’t realize that meeting the Paris goal of 1.5-2 degrees means getting to zero emissions. “Balance of sources and sinks” is a bit technical for most people, but “zero” is a number everyone understands. Post-Paris this needs to be made clear - an economy based on dumping CO2 into the atmosphere has to end and the clean energy economy must begin, not in some distant future, but in the coming decades. - ERIC BEINHOCKER AND MYLES ALLEN