Kirsten Zickfeld

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Concern has been expressed that anthropogenic climate change may lead to a slowdown or even collapse of the Atlantic thermohaline circulation (THC). Because of the possibly severe consequences that such an event could have on the northern North Atlantic and northwestern Europe, integrated assessment models (IAMs) are needed to explore the associated(More)
The global temperature response to increasing atmospheric CO(2) is often quantified by metrics such as equilibrium climate sensitivity and transient climate response. These approaches, however, do not account for carbon cycle feedbacks and therefore do not fully represent the net response of the Earth system to anthropogenic CO(2) emissions. Climate-carbon(More)
Multimillennial simulations with a fully coupled climate–carbon cycle model are examined to assess the persistence of the climatic impacts of anthropogenic CO2 emissions. It is found that the time required to absorb anthropogenic CO2 strongly depends on the total amount of emissions; for emissions similar to known fossil fuel reserves, the time to absorb(More)
Avoiding "dangerous anthropogenic interference with the climate system" requires stabilization of atmospheric greenhouse gas concentrations and substantial reductions in anthropogenic emissions. Here, we present an inverse approach to coupled climate-carbon cycle modeling, which allows us to estimate the probability that any given level of carbon dioxide(More)
[1] The stability of the Indian summer monsoon is investigated by means of a box model of the tropical atmosphere. At the heart of this model is the moistureadvection feedback which allows for the existence of two stable regimes: besides the ‘‘wet’’ summer monsoon, a stable state exists which is characterized by low precipitation. The model is employed for(More)
The aim of this paper is to present a modeling framework for deriving emissions corridors that preserve the Atlantic thermohaline circulation (THC). The framework consists of a multi-gas reduced-form climate model coupled to a four-box THC model and allows for the main physical uncertainties (i.e., climate and North Atlantic hydrological sensitivity) to be(More)
We present results from detailed interviews with 12 leading climate scientists about the possible effects of global climate change on the Atlantic Meridional Overturning Circulation (AMOC). The elicitation sought to examine the range of opinions within the climatic research community about the physical processes that determine the current strength of the(More)
There is uncertainty about the response of the climate system to future trajectories of radiative forcing. To quantify this uncertainty we conducted face-to-face interviews with 14 leading climate scientists, using formal methods of expert elicitation. We structured the interviews around three scenarios of radiative forcing stabilizing at different levels.(More)
[1] A coupled atmosphere-ocean-carbon cycle model is used to examine the long term climate implications of various 2050 greenhouse gas emission reduction targets. All emission targets considered with less than 60% global reduction by 2050 break the 2.0 C threshold warming this century, a number that some have argued represents an upper bound on manageable(More)
22 This paper summarizes the results of an intercomparison project with Earth System Models 23 of Intermediate Complexity (EMICs) undertaken in support of the Intergovernmental Panel 24 on Climate Change (IPCC) Fifth Assessment Report (AR5). The focus is on long-term 25 climate projections designed to: (i) quantify the climate change commitment of di↵erent(More)