North Australian FISH FINDER TM forums

Demonstrates the current warming trend very well ... you may have to click on it to see the animation.

Milankovitch cycles and global warming

https://en.wikipedia.org/wiki/Milankovitch_cycles

Problem is that the solar cycle is in a cooling phase and yet the planet is getting warmer.

No. Its not in a cooling phase at all.

The tropics are headed towards each other at 34 metres per year as the planet stands straighter.

That means there's more solar radiation between the tropics (reef bleaching).

It also means that the extreme ends of the earth (polar regions) are getting marginally closer to the sun.

Everything is getting warmer.

Milankovitch rules!

If so, I'd say that plus the CO2 add up to interesting times for our kids and their grandkids Ron

Yep.

The Tropic of Capricorn locates between Rosedale (near Bundaberg) to Clairview (150km north of Rocky) and back to Rosedale in a 41000 year cycle.

Currently the tropic is about 4km south of Rocky and heading north. The tropic is about 10,000 years into a 20,500 year northerly trip. When it reaches Clariview in 10,000 years time, the earth will stop straightening its lean(obliquity) and start to lean over a bit more. The tropic will head back to Rosedale which will take 20,500 years. The earth will then start to cool again.

On Gladstone Rd Rocky ( southern outskirts), I volunteer at the tourist/visitor information centre which is marked with a 15 metre alloy tropic marker. Its the convenient "tourist" tropic marker for photo opportunities and they can also receive a nice little certificate. I estimate that by the year 2261 (or so) the tropic will have shifted to the right spot making the marker temporarily correct.

With the popularity of GPS navigation units these days, we sometimes get a tourist who'll come in arguing. They're right but we can't have "Mexicans" telling us we're stupid.

After about 10 minutes of discussion about obliquity, precession and the procession of the equinoxes, they leave scratching their heads with a more enlightened view. Confused rather than enlightened I suspect.

About a year ago, I watched a documentary which described the Milankovitch cycle as Ron has. I think it was produced by the BBC (Earth?), though I am not sure whether it was Attenborough or not. Check out Google, there is heaps of information out there.

The documentary showed how this cycle was a major driver of climate change, so much so that up until a few thousand years ago, much of the Sahara desert was woodland forests. So despite anything we do (and we should be doing), there will always be global warming and climate change.

In the 1970s they were worried an ice age was coming. In the 1980s it was Acid Rain. In the 1990s it was all about the hole in the ozone. In the early 2000s it has been all about global warming. Global warming is a convenient truth for legislators.

Wish it was so but on AGW the evidence is overwhelming.

http://ossfoundation.us/projects/enviro ... tch-cycles

Unfortunately, there is still enough doubt out there about AGW - plus the fact it is regarded as the future person's problem - that by the time it is obvious action is needed it will be too late to do much about it. Perfect storm with the "big waves" just starting to form.

http://ossfoundation.us/projects/enviro ... tch-cycles

That's a good comparison and it is pretty clear where the deviation occurs, I had yet to see a graphic that actually showed that before.

Perfect storm with the "big waves" just starting to form.

Yep, now we have "bomb cyclones" forming causing cold snaps in northern hemisphere. I think I saw a movie where that happened before.

Yes, saw that about the so-called bomb cyclones. Dunno what it means re AGW but the Arctic ice graph is at record lows now despite the intense cold over the USA/Canada.

Euro and US cold snaps might be explained by this ... https://www.theguardian.com/environment ... ture-rises

Fascinating story about the end of the Permian period... http://www.bbc.co.uk/science/horizon/20 ... rans.shtml