Net Global Radiative Imbalance

Improvements in characterizing global interannual variation and trend in global heat flux.

Yes there probably is an upward trend. There is substantial uncertainty in the vertical axis offset, though it probably is warming.

And yes, El Nino years are cooling years. Does this surprise you?

Screen Shot 2014-08-10 at 6.47.38 PM

Allan, R. P., C. Liu, N. G. Loeb, M. D. Palmer, M. Roberts, D. Smith, and P.-L. Vidale (2014), Changes in global net radiative imbalance 1985–2012, Geophys. Res. Lett., 41

DOI: 10.1002/2014GL060962

Carbon budget arguments

A slightly more complicated graph following up on the previous one showing how much carbon is left to burn, showing that even that one is unreasonably optimistic.

The curve plots a reasonable estimate of the (Bayesian) probability, given available knowledge, of staying within 2 degrees C above the preindustrial global mean surface temperature. Normally, we base our estimates on the 50% line; to have a 50/50 shot of staying under 2 C, we have used up a bit over half of our available emissions.

Screen Shot 2014-07-04 at 11.06.28 AM

As David Spratt explains, we don’t fly in an airplane with a 1 in 100,000 chance of falling out of the sky. (We have government regulations for that!) But the usual carbon budget is based on a 50% chance of staying within 2 C of warming. If we take a more, ahem, conservative approach, and stick to only a 10% chance of failure, there is no carbon budget left.

I think there are things that mitigate Spratt’s position. But we shouldn’t forget that in the limit of having perfect information about the system, there’s a something on the order of a 10% chance that we may have already passed the 2 C mark by any reasonable definition.

Uh-Oh: Greenland Surface Melting off to a Quick Start

Tom Yulsman in Discover Magazine:

It’s too soon to tell whether this is just a flash in the pan or the start of a really big melt year. There are examples in the past when “brief spikes of 30 and 40 percent occurred even though the year turned out to be fairly normal,” [NSIDC lead scientist] Scambos told me…greenland_melt_area_plot2

That said, “Persistence at this level would get my attention,” Scambos says.

The Current El Nino Picture

via Kevin Trenberth


It’s early days and it may not pan out, but we’re still on track for a Super-ENSO.

The image (Slide 43 in this briefing) shows the evolution of the equatorial temperature anomaly through time in the two super-El-Ninos in the observational record, and the evolution to date of the current likely El Nino.

UPDATE: Peter Sinclair has more