Antinuclear

Extreme weather, sea level, and links to climate change

It turns out if you add up all the rain that occurred there, it is equivalent to taking 2.5mm out of the global ocean and dumping it on Australia. The consequence was there was a big lake that was formed in the middle of Australia which you call Lake Eyre. This is pretty remarkable that you can actually lower the global sea level by this amount just by dumping so much water on land.”

Trenbeth on extreme weather and its links to climate change

The lecture is well worth watching in full as Trenbeth explains changes in the climate system and impacts on extreme weather events.

Kevin Trenbeth on the 2011 sea level bump and Australia’s wettest 2 year period, Indymedia 1 April 13“……….Here is what Trenbeth had to say on the sea level bump and Australia’s rainfall in 2010 and 2011:

“…….sea level goes up with warming both because the ocean is expanding and because there is more ice on land melting going into the ocean to fill the ocean up. Overall it is going up at a rate of 3.1mm per year. So a steady rise overall for this record.”

“Something like 55mm since the record began and this is when we launched into space a series of satellites in the different colours here that are looking down making measurements of the global sea level to millimetre accuracy using an altimetre…….

“What actually happened in this period. Looking now at January to April of 2011 versus 2010…. all this rain that occurred in Australia. Rains down here and up in Northern Siberia, the Missouri flooded in North America as a consequence of very very heavy snows at this time, and the tremendous amount of rains that occurred in Columbia and Venezuela. What actually happened here is that there was sufficient water taken out of the ocean and dumped on land in this event. This was a unique event, in recorded history at least, to lower the sea level by 5mm.

“The most spectacular example of this was what actually happened in Australia…... spots was where it was the wettest on record for this period. All the rest of Australia except for the south-west was in the top ten percentile, in other words it was very wet in those regions as well. It turns out if you add up all the rain that occurred there, it is equivalent to taking 2.5mm out of the global ocean and dumping it on Australia. The consequence was there was a big lake that was formed in the middle of Australia which you call Lake Eyre. This is pretty remarkable that you can actually lower the global sea level by this amount just by dumping so much water on land.”

Trenbeth elaborated that climate scientists can’t tell whether climate change is impacting the operation of El Nino (ENSO) as climate models are at present unable to sufficiently model the phenomenon. “It may well be that it is changing, but we can’t really tell. We do know that the floods and the droughts that go along with El Nino and La Nina are getting more severe in parts of the world. So that is probably the best interpretation we can give as to what is actually going on. ” he said……..

Trenbeth on extreme weather and its links to climate change

The lecture is well worth watching in full as Trenbeth explains changes in the climate system and impacts on extreme weather events. In Particular he focuses on the 2010 Russian Heatwave, the 2009 Black Saturday bushfires, increasing record sea surface temperatures (SSTs), Flooding in Queensland in January 2011 which innundated Brisbane and a third of Queensland declared a disaster area, deals with the 2011-2012 back to back La Nina, one of the strongest on record, which moved so much water from the oceans to the land that a drop in global sea level of 5mm was recorded.

Here is Kevin Trenbeth explaining the basics at about 20 minutes into the video:

“Let’s talk about what is actually happening physically in terms of climate change. Carbon dioxide is increasing in the atmosphere, the greenhouse gases are increasing. So what does that do? Well Carbon dioxide is a greenhouse gas which means it helps to trap some of the energy that would normally escape to space. Infrared radiation that would normally go back to space. Scientists call this radiative forcing. If you estimate what that is, it turns out it is quite small. The effect of the greenhouse gases in the atmosphere is about 1 to 2 per cent of the natural flow of energy through the climate system. And so on a day to day basis this is actually not something that you would perceive in any way. But it is always going in the same direction. It is always producing a warming.”

“Now the main place where that accumulates is in the oceans, so the oceans are systematically warming up, sea levels are rising as a consequence of expansion of the oceans. In addition there is a lot of ice melting on land filling up the oceans which also contributes to sea level rise. If we look at the accumulative affects for the ocean we see that the ocean temperatures have indeed warmed up and ice has melted and the atmosphere above the oceans is warmer and it turns out is also moister. ……” http://indymedia.org.au/2013/04/01/kevin-trenbeth-on-the-2011-sea-level-bump-and-australias-wettest-2-year-period

April 1, 2013 - Posted by Christina Macpherson | Uncategorized