Will USA wake up soon that climate change is already here?

On the fires in Texas - like the 2009 fires in Victoria - more precautionary burning wouldn't have made much difference. And it would probably have been dangerous to attempt it any time in the past 12 months - too dry. From Jeff Masters:

As I reported in yesterday's post, there has never been a Texas summer hotter than the summer of 2011. The summer of 2011 now holds every major heat record for the city of Austin, including most 100° days (67 so far), hottest month in recorded history (August, breaking the previous record by a remarkable 2.1°), hottest summer (by 1.1°), and hottest day in history (112°F, tied with Sep, 5, 2000.)

As wunderground's weather historian Christopher C. Burt documents in his latest blog post, the situation is similar across the rest of the state. Seventeen major cities in Texas recorded their hottest summer on record in 2011. Most of these stations had records extending back more than 100 years, and several of the records were smashed by an amazing 3.4°F--at Lubbock and at Wichita Falls.

Neighboring states also experienced unprecedented heat, withOklahoma recording America's hottest month by any state in recorded history during July, and Shreveport, Louisiana breaking its record for hottest month by 3°F in August. Mr. Burt commented to me: " I do not believe I have ever seen a site with a long period of record, like Shreveport, where records go back to 1874, break its warmest single month on record by an astonishing 3°. This is unheard of. Usually when a site breaks its single month temperature record, we are talking about tenths of a degree, rarely a whole degree, let alone 3 degrees! Hard to believe, frankly."

Texas has also had its worst fire season on record, with over 3.5 million acres burned this year, and it's driest 1-year period in recorded history.

While people are trying to control the Texas fires, rain is pelting down elsewhere. More from Jeff Masters:

An extreme rainfall event unprecedented in recorded history has hit the Binghamton, New York area, where 7.49" fell yesterday. This is the second year in a row Binghamton has recorded a 1-in-100 year rain event; their previous all-time record was set last September, when 4.68" fell on Sep 30 - Oct. 1, 2010. Records go back to 1890 in the city.

The skies have now cleared in Binghamton, with this morning's rain bringing the city's total rainfall for the 40-hour event to 9.02". However, another large region of rain lies just to the south in Pennsylvania, and all of the rivers in the surrounding region are in major or record flood.

The Susquehanna River at Binghamton is at 25.18', its highest level since records began in 1847, and is expected to overtop the flood walls protecting the city this afternoon. In Hershey, Pennsylvania, Swatara Creek is 18' over flood stage, and more than 8' above its record flood crest. Widespread flash flooding is occurring across the entire area, and over 125,000 people have been evacuated from their homes.

And read the comments here on ClimateProgress for more about what rainfall records are being broken around the world.

For how long does CO2 stay up in the air?

This article in Nature discusses the length of time it's likely that CO2 stays up in the air. It's a very long time. Some of it stays around for thousands and thousands of years.

Some people find it hard to understand why CO2 makes a difference to warming. (I've already outlined a simple description of why the earth is warming.)

CO2 warms the earth because of its greenhouse properties. Greenhouse gases are the ones that stop the earth from turning into an ice block. They keep us nice and warm so that we can grow crops, go swimming and do a host of things that would be impossible if the earth was too cold.

Because we keep adding CO2 to the atmosphere by digging up fossil fuels and removing trees, the earth is getting warmer. Because the earth is getting warmer, the amount of water vapour in the air increases. Water vapour in the air can't be seen. It's just another gas.

When water vapour condenses, it forms clouds and we can certainly see clouds but that's no longer water vapour. Clouds are made up of drops of liquid water or ice. Clouds don't have a greenhouse effect as such. Some of them cool the earth and some of them warm the earth. On balance, they don't make much difference to the temperature overall.

Water vapour, on the other hand, is another greenhouse gas so it also makes the earth warmer. That means that now there are two gases that have increased in the air, making the earth warmer - the extra water vapour plus the extra CO2. So the earth gets even warmer than if only one of these greenhouse gases was increasing.

If the earth wasn't getting warmer, the amount of water vapour on average wouldn't change. In fact, water vapour recycles through the air every few days. So if we could cool the earth a bit the amount of water vapour would lessen and the temperature of the earth would drop back to what it used to be like a few years ago.

Unfortunately, it's not easy to cool the earth. One way would be to soak up the extra CO2 in the air. Some scientists are working on how this could be done. But at the moment even if it could be done it's expensive and could have unwanted effects. In any case, we'd have to soak up more than we're putting up in the air to make any difference.

That's why, for now, the best thing to do is to switch over to renewable energy sources as soon as we can, and stop digging up fossil fuels.

For more information on climate change, check out the links on this site.