Sentences with phrase «ar4 uncertainty ranges»

Two, was there any explanation of the discrepancy between the AR4 uncertainty ranges as originally published compared to AR5 Figure 1.4?

It would not have occurred to me to suggest that they delete both figures, concoct a new one that obscures the AR4 uncertainty ranges in a spaghetti format, and double down on text that claims the observations match the models.

For total aerosol forcing using the AR4 uncertainty ranges for individual components, the 90 % confidence range, by quadrature, is ± 0.86 W / m2 (see Table 4).

So... what is the official IPCC apologist explanation for the doubling of the AR4 uncertainty range, which is obviously unexplained in the actual text and chart?

Not exact matches

It is not all that earthshaking that the numbers in Schmittner et al come in a little low: the 2.3 ºC is well within previously accepted uncertainty, and three of the IPCC AR4 models used for future projections have a climate sensitivity of 2.3 ºC or lower, so that the range of IPCC projections already encompasses this possibility.

Cloud responses are more uncertain and that feeds in to the uncertainty in overall climate sensitivity — but the range in the AR4 models (2.1 to 4.5 deg C for 2xCO2) can't yet be constrained by paleo - climate results which have their own uncertainties.

There are reasons why the AR4 runs did not span the whole possible space of aerosol forcings & sensitivity (e.g., Kiehl, 2007, GRL) and thus do not sample the full range of uncertainty.

AR5 SOD Figure 1.5 with annotations showing HadCRUT4 (yellow) and uncertainty ranges from AR4 Figure 10.26 in 5 - year increments (red + signs).

All that is shown for AR4 are 2035 uncertainty ranges for three AR4 scenarios (including A1B) in the right margin, plus a spaghetti of individual runs (a spaghetti that does not correspond to any actual AR4 graphic.)

In the annotated version shown below, I've plotted the AR4 Figure 10.26 A1B uncertainty range in yellow.

(The use of SCMs for the «likely range» allowed the consideration of uncertainties in climate - carbon cycle feedbacks, which were not included in the GCMs in AR4, and also allowed more emissions scenarios to be quantified.)

If IPCC intended this range of projections to represent their uncertainty range, then that is what they should have shown in AR4 Figure 10.26 (which is more consistent with the Technical Summary than the range in the spaghetti graph.)

Figure 3: Global average radiative forcing in 2005 (best estimates and 5 to 95 % uncertainty ranges) with respect to 1750 (IPCC AR4).

• Poles to tropics temperature gradient, average temp of tropics over past 540 Ma; and arguably warming may be net - beneficial overall • Quotes from IPCC AR4 WG1 showing that warming would be beneficial for life, not damaging • Quotes from IPCC AR5 WG3 stating (in effect) that the damage functions used for estimating damages are not supported by evidence • Richard Tol's breakdown of economic impacts of GW by sector • Economic damages of climate change — about the IAMs • McKitrick — Social Cost of Carbon much lower than commonly stated • Bias on impacts of GHG emissions — Figure 1 is a chart showing 15 recent estimates of SCC — Lewis and Curry, 2015, has the lowest uncertainty range.

Have you actually seen the uncertainty range in the AR4's RF distribution in Chapter 2?

They use a group of climate models — characterized as «an ensemble of opportunity» in AR4 — that don't reflect the full range of uncertainty in our knowledge of climate sensitivity.