Sentences with phrase «term changes in solar irradiance»

Overall, in the absence of major volcanic eruptions and, assuming no significant future long term changes in solar irradiance, it is likely (> 66 % probability) that the GMST -LCB- global mean surface temperature -RCB- anomaly for the period 2016 — 2035, relative to the reference period of 1986 — 2005 will be in the range 0.3 °C — 0.7 °C -LCB- 0.5 °F — 1.3 °F -RCB-(expert assessment, to one significant figure; medium confidence).

Long - term changes in solar irradiance were suspected as early as the mid-nineteenth century (Smyth 1855).

-- The smaller RF is due to a re-evaluation of the long - term change in solar irradiance, namely a smaller increase from the Maunder Minimum to the present.

Not exact matches

During the solar minimum of 2008, the value of total solar irradiance at 1 AU (TSI) was more than 0.2 Wm - 2 lower than during the last minimum in 1996, indicating for the first time a directly observed long - term change.

However, they do argue that the reconstruction reflects long - term changes in «orbital configurations» that have continually reduced Northern Hemisphere summer «insolation» (solar irradiance) over the past two millennia.

As John discussed in his post, there are some issues with this hypothesis (i.e. we know observed forcings like solar irradiance and aerosols can explain most past short - term temperature changes without requiring major contributions from these «climate shifts»).

In order to reliably interpret surface temperature variations we need a good idea of all the causal factors, including El Niño, solar irradiance, volcanic eruptions, observational biases, changes in ocean circulation and possible long term oscillationIn order to reliably interpret surface temperature variations we need a good idea of all the causal factors, including El Niño, solar irradiance, volcanic eruptions, observational biases, changes in ocean circulation and possible long term oscillationin ocean circulation and possible long term oscillations.

The latter, however, probably do not affect climate in the same manner as long term global forcing from atmospheric changes in CO2 (and probably from solar irradiance changes as well).

http://www.agci.org/docs/lean.pdf «Global (and regional) surface temperature fluctuations in the past 120 years reflect, as in the space era, a combination of solar, volcanic, ENSO, and anthropogenic influences, with relative contributions shown in Figure 6.22 The adopted solar brightness changes in this scenario are based on a solar surface flux transport model; although long - term changes are «50 % larger than the 11 - year irradiance cycle, they are significantly smaller than the original estimates based on variations in Sun - like stars and geomagnetic activity.

It was recently speculated that long term changes in the solar interior due to planetary gravitational perturbations may produce gradual multi-decadal and secular irradiance changes (e.g.: Abreu et al. 2012; Charbonneau 2013; Scafetta 2012b, c; Scafetta and Willson 2013a, b, c).

Solar irradiance measurements from 1978 to 2013 will have sampled only three 11 - year irradiance cycles, which alone is insufficient time to determine whether long - term irradiance trends occur or to quantify the broad range of irradiance changes possible in activity cycles of varying strength.