A common argument is that climate change can be avoided if everyone makes a number of small changes in their lives. These guys have determined that marginal, easily affordable changes in people's lives are insufficient according to some climate models. (Unless there's are large, unforeseeable technological advances.)
In other words, a specific approach or category of approaches won't work if you believe the forecasts of some severe climate models. The obvious response would be to stop advocating the unworkable approaches and/or re-examine the climate models to see if they might be overestimating the challenge.
Perhaps the article communicates this poorly. It's still useful info though.