Seasonally planet Earth is hottest in July. Northern summers are hotter because of the greater land mass in the Northern Hemisphere. This July was a scorcher, being the hottest single month since records began:

The cool spot below Greenland is now average.

This graph shows how the seasonal variation goes since 1880:

NASA GISS chief Gavin Schmidt said:

he expects July will be the last record hot month of this year as the residual heat from an exceptionally strong El Niño dies away. Though El Niño itself was declared over in June, global temperatures tend to lag by about two to three months.

He’s 99% certain 2016 will be a record year:

We are now in the process of leaving the 20th century climate behind:

Malcolm Roberts on Q&A, as you probably know, told astrophysicist Brian Cox that he wasn’t impressed with graphs like that. The data has been corrupted by conspiratorial scientists, he says, thousands of them, working to a song sheet developed by shadowy powerful people trying to manipulate us into a world government.

Such propositions don’t pass the common sense test.

The link made reference to:

[Professor] Richard Muller, a former prominent sceptic US scientist, re-examined 14 million temperature observations from 44,455 sites across the world going back to 1753. The results prompted a “total turnaround” in his views.

This is a reference to the large Berkeley Earth Surface Temperature project (BEST) back in 2011, which sceptic Anthony Watts said he would accept while the project was underway. However, it came up with the ‘wrong’ answers, so he didn’t.

In the real world it seems that a step change might be happening, as alluded to in this post of June 2015, which carries a graph showing a five-year running mean:

Roger Jones, who has been working seriously on the science of the step change hypothesis, now has a post up explaining it in simple language which will link to some heavy duty papers as they roll out. He thinks:

We are in the middle of the next big shift right now. As this El Niño settles back into a more normal pattern we will find the shallow oceans and atmosphere are appreciably warmer than they were between 1997 and 2014. Things might be stable for a few years, who knows?, but another one will be on the way somewhere down the track. Previous step changes were 1968-70 southern hemisphere, 1979-80 global, 1987-88 northern hemisphere and 1997-98 global.

Every one of these step changes takes the world into new territory. So far this time, it’s been the biggest mangrove die-off ever seen in northern Australia, kelp forests of south-west WA killed off by record warm waters, the largest coral bleaching yet witnessed and unprecedented wildfires in North America. And that’s the short of it.

Whether you take the stairs or the elevator, temperatures are still going up. I think Jones’ concentration on the change-up points should be a prelude to examining how the mechanisms of heat transfer on a large scale between the ocean and the atmosphere and surface temperature work, with patterned but essentially chaotic systems at play.

The step change hypothesis in not a trivial matter. This view of the climate implies greater risk, and until we understand better what is going on, greater uncertainty.

RealClimate has taken a quick look between model performance and the real world:

And:

Not bad, generally speaking, but the forecast shows an elevator, whereas we seem to be on the stairs.

Dana Nuccitelli reminds us that climate change occurs over long periods – from the carbon pollution we’ve already put into the atmosphere, we’re committed to 1.5–3°C warming over the coming decades and centuries.

Curt Stager’s Deep Future: The Next 100,000 Years of Life on Earth published by Scribe back in 2011 says the optimistic scenario is that it would take 100,000 years for the planet to return to ‘normal’ if we get CO2 under control quickly.

Finally, a recent study found that in 70 years, by 2080, few cities outside Europe could host a summer Olympic Games:

only eight cities in the Northern Hemisphere — outside of Western Europe — will have a cool enough climate to host the summer games. No cities in Latin America or Africa would be viable hosts for the games, and only three North American cities — Calgary, Vancouver, and San Francisco — would qualify.

A 2014 study found that by 2050-80 somewhere between six and ten of the past 19 winter games hosts would have enough snow:

Host cities for the Winter Olympics have already faced issues related to warming weather. In 2014, temperatures in Sochi reached 68 degrees Fahrenheit, making it the warmest winter games in history. In 2010, organizers at the Vancouver games had to bring in snow, airlifting it by helicopter and hauling it in by the truckload to ensure that there was enough powder to keep the games running.