Strong present-day aerosol cooling implies a hot future

  title={Strong present-day aerosol cooling implies a hot future},
  author={Meinrat O. Andreae and Chris D. Jones and Peter M. Cox},
Atmospheric aerosols counteract the warming effects of anthropogenic greenhouse gases by an uncertain, but potentially large, amount. This in turn leads to large uncertainties in the sensitivity of climate to human perturbations, and therefore also in carbon cycle feedbacks and projections of climate change. In the future, aerosol cooling is expected to decline relative to greenhouse gas forcing, because of the aerosols' much shorter lifetime and the pursuit of a cleaner atmosphere. Strong… 
Observed climate change constrains the likelihood of extreme future global warming
If cooling due to present-day levels of atmospheric aerosol is suppressing global temperatures, future reductions in aerosols emissions would allow the full greenhouse gas induced warming to be
Atmospheric aerosols versus greenhouse gases in the twenty-first century
  • M. Andreae
  • Environmental Science
    Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2007
The end of significant climate protection by atmospheric aerosols, combined with the potentially very high sensitivity of the climate system, makes sharp and prompt reductions in greenhouse gas emissions, especially CO2, very urgent.
Effect of aerosol radiative forcing uncertainty on projected exceedance year of a 1.5 °C global temperature rise
Anthropogenic aerosol emissions are predicted to decline sharply throughout the 21st century, in line with climate change and air quality mitigation policies, causing a near-term warming of climate
Lethargic Response to Aerosol Emissions in Current Climate Models
The global temperature trend observed over the last century is largely the result of two opposing effects—cooling from aerosol particles and greenhouse gas warming. While the effect of increasing
Why does knowledge of past aerosol forcing matter for future climate change?
Aerosol particles scatter and absorb radiation and interact with cloud particles. The net aerosol forcing since preindustrial times is negative and has offset part of the greenhouse gas warming. It
On the additivity of climate response to anthropogenic aerosols and CO2, and the enhancement of future global warming by carbonaceous aerosols
Climate responses to aerosol forcing at present-day and doubledCO2-levels are studied based on equilibrium simulations with the CCM-Oslo atmospheric GCM coupled to a slab ocean. Aerosols interact
Large contribution of natural aerosols to uncertainty in indirect forcing
A sensitivity analysis on a global model is performed to quantify the uncertainty in cloud radiative forcing over the industrial period caused by uncertainties in aerosol emissions and processes and suggests that improved measurements and evaluation of simulated aerosols in polluted present-day conditions will not necessarily result in commensurate reductions in the uncertainty of forcing estimates.
Unrealized Global Temperature Increase: Implications of Current Uncertainties
Unrealized increase in global mean surface air temperature (GMST) may result from the climate system not being in steady state with forcings and/or from cessation of negative aerosol forcing that
Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols
Abstract. Atmospheric aerosols and greenhouse gases affect cloud properties, radiative balance and, thus, the hydrological cycle. Observations show that precipitation has decreased in the
Reducing the Uncertainties in Direct Aerosol Radiative Forcing
  • R. Kahn
  • Environmental Science
    Surveys in Geophysics
  • 2011
Direct aerosol radiative forcing (DARF) remains a leading contributor to climate prediction uncertainty. To monitor the spatially and temporally varying global atmospheric aerosol load, satellite


Climate Forcing by Aerosols--a Hazy Picture
Anthropogenic aerosol emissions are believed to have counteracted the global-warming effect of greenhouse gases over the past century. However, the magnitude of this cooling effect is highly
Climate Forcing by Anthropogenic Aerosols
The aerosol forcing has likely offset global greenhouse warming to a substantial degree, however, differences in geographical and seasonal distributions of these forcings preclude any simple compensation.
Global indirect aerosol effects: a review
Abstract. Aerosols affect the climate system by changing cloud characteristics in many ways. They act as cloud condensation and ice nuclei, they may inhibit freezing and they could have an influence
Constraints on radiative forcing and future climate change from observations and climate model ensembles
A Monte Carlo approach is presented to produce probabilistic climate projections, using a climate model of reduced complexity and the input parameters and in the model itself are taken into account, and past observations of oceanic and atmospheric warming are used to constrain the range of realistic model responses.
Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model
Results from a fully coupled, three-dimensional carbon–climate model are presented, indicating that carbon-cycle feedbacks could significantly accelerate climate change over the twenty-first century.
Estimates of the direct and indirect radiative forcing due to tropospheric aerosols: A review
This paper reviews the many developments in estimates of the direct and indirect global annual mean radiative forcing due to present‐day concentrations of anthropogenic tropospheric aerosols since
Positive feedback between future climate change and the carbon cycle
Future climate change due to increased atmospheric CO2 may affect land and ocean efficiency to absorb atmospheric CO2. Here, using climate and carbon three‐dimensional models forced by a 1% per year
Transport and direct radiative forcing of carbonaceous and sulfate aerosols in the GISS GCM
We simulate the major anthropogenic aerosols, sulfate, organic carbon and black carbon, in the Goddard Institute for Space Studies General Circulation Model (GISS GCM), and examine their transport,
Attribution of twentieth century temperature change to natural and anthropogenic causes
Abstract  We analyse possible causes of twentieth century near-surface temperature change. We use an “optimal detection” methodology to compare seasonal and annual data from the coupled
Climate change 2001 : the scientific basis
Summary for policymakers Technical summary 1. The climate system - an overview 2. Observed climate variability and change 3. The carbon cycle and atmospheric CO2 4. Atmospheric chemistry and