The climate problem can be characterized by a curious concurrence of phenomena: universal agreement that something bad or even catastrophic might be happening, and universal inability to manage risks ex ante. This dilemma can, in a nutshell, be attributed to the fact that substantial costs of reducing human forcing of climate change would start biting now, but evidence of benefits from early action will remain cloudy for decades and worst effects might not be felt for centuries. We argue that due to ignorance about Abrupt Climate Change (ACC) and Negative Emission Technologies (NET) in the assessment of climate risk management strategies, the scientific and political discussion has so far been socially constructed.

We show that the only GHG concentration policy in conformity to the UNFCCC is to bring concentrations back to its stable bounds within which it oscillated for the past 420 thousand years. A low GHG concentration target will not only minimize the risk of irreversible extreme weather and abrupt climate events, but also reduce the associated uncertainties. We will illustrate this point by simulations of ecosystem collapse and economic underdevelopment induced by events of ACC.

Despite enormous efforts in building emission scenarios, the attainability of such an obvious concentration target has never been assessed. We are able to show that NET, that have been so far ignored in GHG control assessments, are an additional option that could enable reduction of atmospheric CO2 concentrations to levels lower than what could otherwise have been achieved within certain time frames. In addition, NET can substantially reduce the cost of low-emission scenarios. NET can, thus, as a preventive mitigation technology help to control risk exposure and improve mankind’s ability to manage climate risks ex ante.