Does climate change cause extreme weather or does it not?

Lubchenco is a Warmer and a political appointee. If she wants to keep her job, she MUST spew the dogma of the Warming religion. Her statements taken as a whole, expose this.

With the first statement that you cite, she tries to come off as having some objectivity. In the second, she suggests that the frequency of what she perceives as climate/weather extremes supports 'climate change' predictions.

In more specific terms:

Propose that A and B cause C, such that C(A,B) = C(A) + C(B).

In a sufficiently complex system (such as climate), or in a system where Cs are indistinguishable (such as small scale physics), then it may not be possible from observations of C(A,B) to determine whether an individual C(A,B) is a C(A) or a C(B).

Identify A as a 'natural climate' parameter, and B as a 'global warming' parameter. If C(A,B) increases for an increase in B, then global warming leads to more extreme weather. However, it might be impossible to attribute individual C(A,B)s to C(A) or C(B). So an individual event may not be blamed on climate change with good certainty.

However, if you know C(A) and C(A,B), you can estimate C(B) and if it is significantly nonzero then you have demonstrated with good certainty that C(B) exists.

Let's take broken temperature records as an example of an 'extreme event'. It is impossible to say that because a city broke its 100 year temperature record on the 23rd September 2006 that this was due to climate change because if there was a 'random' basic climate there is still a 1 in 100 chance that it would have been broken anyway - and you'd expect 3-4 record breaking days a year. If you get 50 a year, then you can be pretty confident that there has been a particularly warm year. Series of particularly record breaking years can statistically demonstrate that C(B) exists with a high level of probability.

This is why statistical studies are done, with results looking like this:

http://www.ucar.edu/news/releases/2009/images/temp...

It might be possible to say with some confidence that an individual event was due to global warming: the 2003 European heatwave and 2010 Russian heatwave were both considered as only being able to occur with something like 1 in a thousand year probability (or less) so it doesn't seem unreasonable to relate the two.

If you've spent much time reading about the environment during the past few years, then at some point you've heard someone say that you can't link individual weather events to climate change. Environmentalists say it when climate deniers point to an unusually bad blizzard or ice storm in an effort to refute global warming, and climate-change deniers say it when environmentalists point to extreme weather events such as worse-than-usual hurricanes or wildfires or droughts as evidence of increasing climate disruption. No matter who is making the claim, they are correct. You can't say with any certainty that a single weather event, no matter how extreme, is a direct effect of climate change.

It's not contradictory at all, it's intentionally ambiguous.

I'll emphasize the ambiguity for you.

"extreme weather events, when viewed individually, should not be considered as firm evidence that climate change was under way" We've seen the same kind of events throughout human history.

"we are seeing, with more and more of these extreme events, is completely consistent with what we would expect to see under a climate-changed world" The models predict that we will have weather.

A single point does not a trend make.

I think she is saying that an individual event is evidence of nothing but the occurrence of that individual event. A collection of events, or in this case an increasing occurrence of events, are suggestive of a driver responsible for the increase of events.

Of course the converse is true as well. If more extreme events are expected under a changing climate then the occurrence of such events supports the hypothesis.

There is no increase in frequency as stated above by another answerer this is typical alarmist crap! There has been no stronger Hurricanes, Tornadoes, Volcanoes, as they are all weaker and less frequent. Pakistan has had floods for hundreds of years, the only reason that this is worse is because there has been a population explosion over there and as a concequence more people are affected. The recent hot spells in Russia are nothing new but its the cold that kills and the record freezing temperatures of last winter do not stack up in a warming world!

These politicians are nothing more than tax collectors hell bent on ruining our way of life!

It is jibberish for politicians to play with. It is meaningless. For example, when she says "we are seeing more and more" obviously that will happen with the passage of time.

"A climate changed world."

I am offended by nonsensisical names like that. They are meant to fool the gullible and the ignorant. Climate change has been happening since there was a climate. Having mealy mouthed politicians pretending it is something new gets my blood boiling. The bottom line is there is no reason to believe that adding greenhouse gases to the atmosphere is going to increase extreme events in my opinion. In fact, if anything, it should reduce the temperature gradient. The only thing different is that we have political hacks attempting to blame US for everything under the sun (except the sun or H2O) for anything bad that happens. What is really amazing is that anyone actually believes it.

Can you explain how they are contradictory? Just read them and they're obviously not. I'll emphasize the key word for you.

"extreme weather events, when viewed *individually*, should not be considered as firm evidence that climate change was under way."

"(what) we are seeing, with more and more of these extreme events, is completely consistent with what we would expect to see under a climate-changed world."

Individual extreme weather events cannot be attributed to or seen by themselves as evidence for AGW, but the increase in their frequency (on average) is consistent with what we expect from AGW. Why is that hard to understand? That's exactly what we're always telling you. Take off your denier glasses and read the statements again.

The denier obsession with terminology is rather pathetic, by the way. I guess when you've lost the scientific argument you have to turn to arguing the terminology.

Just read them. They are not contradictory at all. No single extreme event can be attributed to climate change. But the models predicted that extreme events will become more common and we already seeing in increase in frequency.

They're just trying to make it look like they matter no matter what.

The more it sounds like meaningless drivel, the more likely it is meaningless drivel.