Global warming 'irreversible' for next 1000 years

WASHINGTON (AFP) — Climate change is "largely irreversible" for the next 1,000 years even if carbon dioxide (CO2) emissions could be abruptly halted, according to a new study led by the US National Oceanic and Atmospheric Administration (NOAA).

The study's authors said there was "no going back" after the report showed that changes in surface temperature, rainfall and sea level are "largely irreversible for more than 1,000 years after CO2 emissions are completely stopped."

NOAA senior scientist Susan Solomon said the study, published in this week's Proceedings of the National Academy of Sciences journal, showed that current human choices on carbon dioxide emissions are set to "irreversibly change the planet."

Researchers examined the consequences of CO2 building up beyond present-day concentrations of 385 parts per million, and then completely stopping emissions after the peak. Before the industrial age CO2 in Earth's atmosphere amounted to only 280 parts per million.

The study found that CO2 levels are irreversibly impacting climate change, which will contribute to global sea level rise and rainfall changes in certain regions.

The authors emphasized that increases in CO2 that occur from 2000 to 2100 are set to "lock in" a sea level rise over the next 1,000 years.

Rising sea levels would cause "irreversible commitments to future changes in the geography of the Earth, since many coastal and island features would ultimately become submerged," the study said.

Decreases in rainfall that last for centuries can be expected to have a range of impacts, said the authors. Regional impacts include -- but are not limited to -- decreased human water supplies, increased fire frequency, ecosystem change and expanded deserts.

“We can’t drive our SUVs and eat as much as we want and keep our homes on 72 degrees at all times … and then just expect that other countries are going to say OK,” Obama said.

“That’s not leadership. That’s not going to happen,” he added.

Sea levels are rising, but they have been rising at least since the early 1800s. In the era of satellite measurements, the rise has not accelerated (actually we've seen a sea-level fall over the past two years). The UN expects about a 30-centimetre sea-level rise over this century — about what we saw over the past 150 years.

In that period, many coastlines increased, most obviously in Holland, because rich countries can easily protect and even expand their territory. But even for oft-cited Bangladesh, scientists just this year showed that the country grows by 20 square kilometres each year, because river sedimentation win out over rising sea levels.

Obama's claim about record droughts similarly fails even on a cursory level — the US has, in all academic estimates, been getting wetter over the century (with the 1930s 'dust bowl' setting the drought high point). This is even true globally over the past half-century, as one of the most recent scientific studies of actual soil moisture shows: “there is an overall small wetting trend in global soil moisture.”

Furthermore, famine has rapidly declined over the past half century. The main deviation has been the past two years of record-high food prices, caused not by climate change but by the policies designed to combat it: the dash for ethanol, which put food into cars and thus upward pressure on food prices. The World Bank estimates this policy has driven at least 30 million more people into hunger. To cite policy-driven famine as an argument for more of the same policy seems unreasonable.

President Barack Obama’s trillion dollar stimulus plan, has morphed into an appropriations bill devoid of debate. The process forgoes any pretense of targeting unemployed people and resources.

For instance, the bill reads “Provided further, That not less than $140,000,000 shall be available for climate data modeling.” This raises the question of how many unemployed climate modelers are out there pounding the pavement.

When presented with that question, last Friday, Pat Michaels, former president of the American Association of State Climatologists stated “I don’t know one unemployed modeler.”

Whether another $140,000,000 for climate data modeling is a good idea, it is hard to see an immediate, economy-stimulating impact from this item.

What’s the rush? Maybe they need to get all their modeling done before another cool year highlights how bad the models are.