I’m beginning to think that the little climate simulation model I’ve been laboriously constructing for the past year may be becoming a bit more relevant than it was when I started on it. And it may be entirely due to newly-elected Democratic Representative Alexandra Ocasio-Cortez.
She’s proposed a Green New Deal:
the resolution says it is the duty of the federal government to craft a Green New Deal “to achieve net-zero greenhouse gas emissions”. That includes getting all power from “clean, renewable and zero-emission energy sources”.
I guess that means burning no more oil or coal at all. Electricity is going to have to be generated with windmills and solar power.
She’s also so worried about climate change that she wonders whether people should have children:.
Democratic Congresswoman Alexandria Ocasio-Cortez argues that it is a “legitimate question” to ask whether it’s moral for people to have children with the looming threat of climate change continues to exacerbate global conflicts.
The freshman New York lawmaker used Instagram to connect with her 2.5 million followers over the weekend to discuss the question she often hears from her younger constituents.
“There’s scientific consensus that the lives of children are going to be very difficult,” Ms Ocasio-Cortez said during an Instagram livestream. “And it does lead young people to have a legitimate question: Is it OK to still have children?”
Ms Ocasio-Cortez, a co-sponsor of the progressive Green New Deal resolution, said the clock is ticking when it comes to reversing the effects of global warming within the estimated 12-year deadline the United Nations Intergovernmental Panel on Climate Change reported last fall.
“We had time when I was born, but — ticktock — nothing got done,” the 29-year-old lawmaker added. “As the youngest member of Congress, I wish we didn’t have 12 years. It’s our lungs that are going to get choked with wildfire smoke.”
So she’s a climate hyper-alarmist who looks set to put Al Gore and Michael Mann in the shade. And she seems to be have become a political superstar since she entered the US House of Representatives last year.
I’ve been building my climate model in order to look at ice ages, because my suspicion is that we’re much more in danger of a new ice age than we are of global warming. Over the past 400,000 years we’ve only had a few brief interglacial periods like our present one, before the ice has rolled back in again. Shouldn’t we be more worried about the return of the ice than a little bit of global warming? Particularly if global warming might delay the onset of a new ice age?
Just a couple of days ago I posted up a graph of the Vostok ice core (click to enlarge). The top graph shows the temperature record over the past 400,000 years. The middle graph shows the CO2 concentrations during the period. And the bottom graph shows the dust concentrations. At the end of the last ice age, CO2 concentrations rose in tandem with temperature. Dust concentrations rose long before temperatures rose. So what melted the ice? Was it CO2, or dust deposition on the ice sheets, or Milankovitch cycles, or asteroid impacts? As far as I can make out, some climate scientists (but not all) think that it was the CO2 that melted the ice 12,000 years ago, and is melting it further again now.
“Melting of the Greenland ice sheet has gone into overdrive,” Trusel, from Rowan University in New Jersey, told ScienceAlert.
“It’s now melting more than at any point in at least the last four centuries, and probably more than at any time in the last 7 to 8 millennia.”…
In fact, if all of it were to disappear in a hot-enough world, we’d be looking at almost 7.5 metres (24 feet) of sea level rise.
Short of rapidly slashing carbon emissions – or wishfully geoengineering the planet somehow – our best proposals for holding off such a disastrous outcome do not seem particularly realistic.
The message is clear: a rise in CO2 concentrations melted the ice 12,000 years ago, and a renewed rise in CO2 concentrations today is melting what little that still remains of the ice. And it’s become a red hot political issue for some people. Nothing else matters. And they’re not worried about any ice age, because they think that the CO2 will melt any ice that shows up.
But do they really know what caused the ice to melt 12,000 years ago? Was it really just CO2 that did it? Couldn’t it have been dust deposition on the ice sheets that reduced their albedo and raised air temperatures? Didn’t a Milankovitch solar heat gain maximum help contribute a further rise n temperature? Might it not have been a whole consortium of different factors that caused the ice to melt?
Do we really understand how ice ages work? The answer, as far as I can see, is that we don’t. Last year I bought Raymond Pierrehumbert’s Introduction to Planetary Climate. He’s a climate scientist, and he writes occasionally on RealClimate.org, so I suppose he must be another climate alarmist. But he doesn’t come over that way in his book. He’s refreshingly candid about how many things are not very well understood, and ice ages are one of them. And he doesn’t think that CO2 brought an end to past ice ages:
Through a study of the radiative physics of ice in a Snowball state, we have understood why it is so hard to get out by a gaseous greenhouse effect of accumulating CO2 alone… (p 625)
But while he’s not sure if CO2 ended the last ice age, he’s sure that it was a contributory factor. He includes dust deposition and Milankovitch cycles as other contributing factors.
Yet Alexandra Ocasio-Cortez seems to be far more certain about it all than Pierrehumbert.
I’m just going to carry on building my simulation model. It’s coming along quite well. I can simulate global warming by raising the absorptivity of air, and I can simulate dust deposition by lowering the albedo of ice. I haven’t got Milankovitch cycles working yet, but I’ve got the current solar regime that the Earth enjoys. And I’ve been dropping hundreds of metres of snow and ice on the surface of the Earth, and getting it to melt. Last week I was simulating persistent snowfall, and this week I’ve been looking at water evaporation rates. Piece by piece, I putting them all together into a dynamic, working model. For it seems to me that that it’s the only way to find answers to any of these questions. And we need to find answers in a world full of hyper-alarmists like Ocasio-Cortez.