Nature Climate Change | Climate Feedback

Cloudy knowledge

darkclouds.jpgDespite decades of research, relationships between clouds, aerosols and precipitation are poorly understood, concludes a review article in Nature today.

Before a cloud can produce rain or snow, rain drops or ice particles must form. Atmospheric aerosols, tiny particles of mineral or organic origin, serve as the nuclei for condensation.

But the precise effects of aerosols on cloud formation and radiative forcing remain controversial. In their review article, Bjorn Stevens and Graham Feingold propose that the uncertainties reflect a failure to take into account processes that act to buffer the response of clouds and precipitation to aerosol changes. Worse, existing tools and methodologies for untangling these processes are inadequate, they say.

“If we wish to make significant strides in understanding the interplay among the aerosol, clouds and precipitation, we consider it imperative to launch significant new international initiatives, with comprehensive, coordinated and enduring measurements, targeting specific regimes and coupled to state-of-the-art modelling,” the duo concludes.

Among other things, they say, what’s lacking is an array of ground-based remote sensors capable of vertically and temporally resolving the aerosols, clouds, precipitation and the meteorological state.

Quirin Schiermeier

Image: Flickr user laffy4k, Creative Common license


  1. Report this comment

    Dr. Gerhard Löbert said:

    After three decades of continual increase, the mean Earth temperature has been decreasing steadily since 2002, as precise satellite measurements show. As a result, the steady rise in sea level has stopped since 2005.

    World climate is a regular quasi-periodic phenomenon (see Fig. 2.1 of ) that is driven by solar activity with a period of 70 – 80 years (Gleissberg cycle). Because of this regularity, it can be stated with absolute certainty that the mean Earth temperature will continue to decrease until 2040.

    1. There exists an extremely close correlation between the changes in the mean global temperature and the small changes in the rotational velocity of the Earth – two physically unrelated geophysical quantities – (see Fig. 2.2 of, which has been ignored by the mainstream climatologists, and leaves little room for a human influence on climate. Note that temperature lags rotation by 6 years. This close correlation results from the action of galactic vacuum density waves on the Sun and on the Earth (see ).

    2. The orbital periods of all Solar System planets are very close to integer multiples and integer fractions of the periods of the well-known solar cycles. This provides further evidence for the existence of super-Einsteinian gravitational waves and of their action on all celestial bodies of the Solar System. In the post of September 26, 2009 in it is shown that all orbital periods of the planets of the Solar System are very close to integer fractions and integer multiples of the periods of the Hale (22.14 years) and the Gleissberg (78 – 84 years) solar cycles.

    The Close Correlation between Earth’s Surface Temperature and its Rotational Velocity as well as the Close Correlation between the Planetary Orbital Periods and the Periods of the Solar Cycles Prove that Climate Changes are Driven by Galactic Gravitational Waves (Vacuum Density Waves)

    Progress in climatological science can only be achieved if the above physical facts are looked into in full depth.

    Ref.: a) The posts of September 19, 2008 and September 26, 2009 in