by Judith Curry
A range of scenarios for global mean surface temperature change between 2020 and 2050, derived using a semi-empirical approach. All three modes of natural climate variability – volcanoes, solar and internal variability – are expected to act in the direction of cooling during this period.
Posted in climate models, Sensitivity & feedbacks, Solar, Uncertainty
by Javier
By knowing or estimating where in the solar cycle we are we can get an estimate of the chances of a particular outcome even years ahead.
Posted in Solar
by Javier
Climate variations that alter the angular momentum of the atmosphere modify the speed of the Earth’s rotation, which affects the length of day (LOD). Alterations in LOD integrate different climate-affecting phenomena, and can anticipate turning points in climate.
Posted in Attribution, Solar
by Javier
Summary: Holocene climate has been affected in different periods by several centennial to millennial solar cycles. The ~ 1000-year Eddy solar cycle seems to have dominated Holocene climate variability between 11,500-4,000 years BP, and in the last two millennia, where it defines the Roman, Medieval, and Modern warm periods. The ~ 208-year de Vries solar cycle displays strong modulation by the ~ 2400-year Bray solar cycle, both in its cosmogenic isotope signature and in its climatic effects. The Centennial, and Pentadecadal solar cycles are observable in the last 400-year sunspot record, and they are responsible for the present extended solar minimum that started in 2008.
Posted in Attribution, Solar
*by Javier
The role of solar variability on climate change, despite having a very long scientific tradition, is currently downplayed as a climatic factor within the most popular hypothesis for climate change.
Posted in Solar
by Judith Curry
We can conclude that the evidence provided is sufficient to justify a complete updating and reviewing of present climate models to better consider these detected natural recurrences and lags in solar processes. – Jorge Sánchez-Sesma
Posted in Solar
by Judith Curry
Climate Dialogue has a very interesting discussion What will happen during a new Maunder Minimum? This is my favorite Climate Dialogue so far.
Posted in Solar
Nevertheless, even if there is such decrease in the solar activity, there is a high confidence that the TSI RF variations will be much smaller in magnitude than the projected increased forcing due to GHG. – IPCC AR5 Chapter 8
by Judith Curry
Two new workshop reports provide insights into what we know and don’t know about the effects of solar variability on climate.
Posted in Solar
by Judith Curry
A very provocative paper by Henrik Svensmark has been published today by the Royal Astronomical Society.
Posted in Solar
by Judith Curry
During the 20th century, solar activity increased in magnitude to a so-called grand maximum. It is probable that this high level of solar activity is at or near its end. It is of great interest whether any future reduction in solar activity could have a significant impact on climate that could partially offset the projected anthropogenic warming. (Jones et al. 2012).
Posted in Sensitivity & feedbacks, Solar
by Judith Curry
So, what’s going on with the sun? The latest research was presented at the Nagoya Workshop on the Relationship between Solar Activity and Climate Changes.
Posted in Solar
by Judith Curry
A new paper is in press that sheds some light on the relationship between cosmic rays and lower tropospheric cloud cover.
Posted in Solar
by Judith Curry
The Annual Meeting of the Solar Physics Division of the American Astronomical Society has announced some very interesting results in this press release entitled “Sun’s fading spots signal big drop in solar activity.”
Posted in Solar
