Human society has developed for thousands of years under one climatic state, and now a new set of climatic conditions are taking shape. These conditions are consistently warmer, and some areas are likely to see more extreme events like severe drought, torrential rain and violent storms.

Deke Arndt, co-editor of the report and chief of the Climate Monitoring Branch of NOAA’s National Climatic Data Center, is quoted in NOAA’s press release:

The temperature increase of one degree Fahrenheit over the past 50 years may seem small, but it has already altered our planet. “Glaciers and sea ice are melting, heavy rainfall is intensifying and heat waves are more common. And, as the new report tells us, there is now evidence that over 90 percent of warming over the past 50 years has gone into our ocean.

Regarding warming oceans, the report says warming has been observed as far as 6,000 feet below the surface, but most of the heat is accumulating in the oceans’ near-surface layers. The implications of a warming ocean are considerable. First, because water expands as it warms, ocean heating is responsible for much of the observed sea-level rise (melting of land-based ice is responsible for the rest). Further, the oceans will hold the heat they’ve accumulated because they warm and cool much more slowly than air – meaning the impacts of warming will continue to be felt long after greenhouse gas emissions peak and begin to decline, should humans ever manage to muster the wisdom and the will to make that happen.

June 2010 was the fourth consecutive month with reported warmest averaged global land and ocean temperature on record (March, April, and May 2010 were also the warmest on record). June 2010 was the 304^th consecutive month with a global temperature above the 20^th century average.

The combined global average land and ocean surface temperature for the January–June period was the warmest such period on record, 0.68°C (1.22°F) above the 20^th century average.

Jeff Masters at Wonder Blog reports nine countries have smashed all-time temperature records so far in 2010:

]S]ix nations in Asia and Africa set new all-time hottest temperature marks in June. Two nations, Myanmar and Pakistan, set all-time hottest temperature marks in May, including Asia’s hottest temperature ever, the astonishing 53.5°C (128.3°F) mark set on May 26 in Pakistan. Last week’s record in Russia makes nine countries this year that have recorded their hottest temperature in history, making 2010 the year with the most national extreme heat records.

This graph shows how global temperatures have been rising over the past 100 years:

The report explains:

Through much of May and June, high pressure dominated the Beaufort Sea with low pressure over Siberia. Winds associated with this pattern, known as the dipole anomaly, helped speed up ice loss by pushing ice away from the coast and promoting melt.

However, the dipole anomaly pattern broke down in early July. In the first half of July, cyclones (low pressure systems) generated over northern Eurasia tracked eastward along the Siberian coast and then into the central Arctic Ocean, where they tend to stall. This cyclone pattern is quite common in summer. The low-pressure cells have brought cooler and cloudier conditions over the Arctic Ocean. They have also promoted a cyclonic (anticlockwise) sea ice motion, which acts to spread the existing ice over a larger area. All of these factors likely contributed to the slower rate of ice loss over the past few weeks.

In the last few days, high pressure has started to build again in the Beaufort Sea, but whether this will continue remains to be seen.

Still, Arctic sea ice extent at this time is the second lowest ever recorded, as seen in this chart from the Japan Aerospace Exploration Agency website, IJIS.

May 2010 Blended Land and Sea Surface Temperature Anomalies in degrees Celsius

The combined global land and ocean surface temperature during March–May 2010 was 14.4°C (58.0°F) and ranked as the warmest such period on record, 0.73°C (1.31°F) above the 20^th century average of 13.7°C (56.7°F).

March 2010 – May 2010 Blended Land and Sea Surface Temperature Anomalies in degrees Celsius

The warmest anomalies occurred over eastern and northern North America, eastern Brazil, northern Africa, eastern Europe, and southern Asia. See the deep red dots along the land masses of the Arctic and in southern Greenland and the eastern U.S. and Canada. Anomalously cool conditions were present over eastern Asia and the western United States.

Looks to be a long, hot summer.

May Global Hemisphere plot

The previous record for the fastest rate of June decline was set in 1999. The linear rate of monthly decline for June over the 1979 to 2010 period is now 3.5% per decade.

Whether or not 2010 will see a new record low set for Arctic sea ice extent depends upon weather patterns. NSIDC explains:

The record low ice extent of September 2007 was influenced by a persistent atmospheric pressure pattern called the summer Arctic dipole anomaly (DA). The DA features unusually high pressure centered over the northern Beaufort Sea and unusually low pressure centered over the Kara Sea, along the Eurasian coast. In accord with Buys Ballot’s Law, this pattern causes winds to blow from the south along the Siberian coast, helping to push ice away from the coast and favoring strong melt. The DA pattern also promotes northerly winds in the Fram Strait region, helping to flush ice out of the Arctic Ocean into the North Atlantic. The DA pattern may also favor the import of warm ocean waters from the North Pacific that hastens ice melt.

June 2010 saw the return of the DA, but with the pressure centers shifted slightly compared to summer 2007. As a result, winds along the Siberian coastal sector are blowing more from the east rather than from the south. Whether or not the DA pattern persists through the rest of summer will bear strongly on whether a new record low in ice extent is set in September 2010.

Ove Hoegh-Guldberg, director of the Global Change Institute at the University of Queensland in Australia and a co-author of the report, says:

This is further evidence we are well on our way to the next great extinction event.

Important conclusions in the report, titled The Impact of Climate Change on the World’s Marine Ecosystems, include:

• The average temperature of the upper level of the oceans has increased more than 1 degree Fahrenheit during the past 100 years, and global ocean surface temperatures in January were the second warmest ever recorded for that month.
• Though the increase in acidity is slight, it represents a “major departure” from the geochemical conditions that have existed in the oceans for hundreds of thousands if not millions of years.
• Nutrient-poor “ocean deserts” in the Pacific and Atlantic oceans grew by 15 percent from 1998 to 2006.
• Oxygen concentrations are dropping off the Northwest U.S. coast and the coast of southern Africa, where dead zones appear regularly. There is paleontological evidence that declining oxygen levels in the oceans played a major role in at least four or five mass extinctions.
• Since the early 1980s, the production of phytoplankton, a crucial part of the food chain, has declined 6 percent, with 70 percent of the decline found in the northern parts of the oceans. Scientists also found that phytoplankton are becoming smaller.

Here’s the abstract:

Marine ecosystems are centrally important to the biology of the planet, yet a comprehensive understanding of how anthropogenic climate change is affecting them has been poorly developed. Recent studies indicate that rapidly rising greenhouse gas concentrations are driving ocean systems toward conditions not seen for millions of years, with an associated risk of fundamental and irreversible ecological transformation. The impacts of anthropogenic climate change so far include decreased ocean productivity, altered food web dynamics, reduced abundance of habitat-forming species, shifting species distributions, and a greater incidence of disease. Although there is considerable uncertainty about the spatial and temporal details, climate change is clearly and fundamentally altering ocean ecosystems. Further change will continue to create enormous challenges and costs for societies worldwide, particularly those in developing countries.

Other factors like mixed-use, street and intersection design, and block size prove to be less important than destination accessibility. Still, these factors are more important than mere density. Density is less important than land-use mix and having shops, schools, and workplaces near to where people live.

Not surprisingly, driving is found to have energy and climate implications:

The transportation outcomes . . .  vehicle miles traveled (VMT) and vehicle trips (VT), are critically linked to traffic safety, air quality, energy consumption, climate change, and other social costs of automobile use.

Figuring out a way to drive less – much, much less – is key to coming to grips with peak oil and to arresting global warming before we reach a tipping point beyond which Earth’s climate will spin out of control, resulting in an Eaarth we no longer recognize and which is no longer fit for human habitation.

The free-access analysis, Travel and the Built Environment, was authored by Reid Ewingab of the University of Utah’s Urban Land Institute; and Robert Cerverocde, University of California (Berkeley) Transportation Center, Institute of Urban and Regional Development.

Here’s the abstract:

Problem: Localities and states are turning to land planning and urban design for help in reducing automobile use and related social and environmental costs. The effects of such strategies on travel demand have not been generalized in recent years from the multitude of available studies.

Purpose: We conducted a meta-analysis of the built environment-travel literature existing at the end of 2009 in order to draw generalizable conclusions for practice. We aimed to quantify effect sizes, update earlier work, include additional outcome measures, and address the methodological issue of self-selection.

Methods: We computed elasticities for individual studies and pooled them to produce weighted averages.

Results and conclusions: Travel variables are generally inelastic with respect to change in measures of the built environment. Of the environmental variables considered here, none has a weighted average travel elasticity of absolute magnitude greater than 0.39, and most are much less. Still, the combined effect of several such variables on travel could be quite large. Consistent with prior work, we find that vehicle miles traveled (VMT) is most strongly related to measures of accessibility to destinations and secondarily to street network design variables. Walking is most strongly related to measures of land use diversity, intersection density, and the number of destinations within walking distance. Bus and train use are equally related to proximity to transit and street network design variables, with land use diversity a secondary factor. Surprisingly, we find population and job densities to be only weakly associated with travel behavior once these other variables are controlled.

Takeaway for practice: The elasticities we derived in this meta-analysis may be used to adjust outputs of travel or activity models that are otherwise insensitive to variation in the built environment, or be used in sketch planning applications ranging from climate action plans to health impact assessments. However, because sample sizes are small, and very few studies control for residential preferences and attitudes, we cannot say that planners should generalize broadly from our results. While these elasticities are as accurate as currently possible, they should be understood to contain unknown error and have unknown confidence intervals. They provide a base, and as more built-environment/travel studies appear in the planning literature, these elasticities should be updated and refined.

The study, Observations beneath Pine Island Glacier in West Antarctica and implications for its retreat, is published in Nature Geoscience.

The 400 meter- high ridge has previously been anchoring the glacier and preventing warm seawater from reaching the ice, melting it from underneath.  A modeling study published in January suggested that once the glacier retreated behind the ridge, the glacier would not be able to recover.

Pine Island glacier is one of a handful in West Antarctica which together are estimated to be responsible for about 10% of global sea-level rise.

At the other end of the world, scientists are predicting that September 2010 will see yet another “critical minimum” for Arctic sea ice.

One forecast, contained in the September Sea Ice Outlook: June Report, was developed by the team from Klima Campus of the University of Hamburg. It estimates a September minimum of 4.7 million square kilometers. Another estimate produced by AWI researchers is a bit higher – 5.2 million km². Neither of the two research groups anticipates that the record minimum of 4.3 million km² in 2007 will be reached. But scientists caution that the decisive factors for the situation in late summer, such as the ice thickness in the central Arctic and further development of the weather in summer, are not yet known.

What is known is that Arctic sea ice volume is falling off a cliff.

Continuously updated Arctic Sea Ice Volume Anomaly from PIOMAS. Daily Sea Ice volume anomalies for each day are computed relative to the 1979 to 2009 average for that day. The trend for the 1979- present period is shown in blue. Shaded areas show one and two standard deviations from the trend. Click on image for a larger version of the figure

]]> http://casafoodshed.org/archives/2010/06/28/ice-is-melting-at-the-ends-of-the-world/feed/ 0 http://casafoodshed.org/archives/2010/06/23/arctic-sea-ice-melting-at-record-pace/ http://casafoodshed.org/archives/2010/06/23/arctic-sea-ice-melting-at-record-pace/#comments Wed, 23 Jun 2010 18:12:41 +0000 jim http://casafoodshed.org/?p=5447 It’s approaching the end of June, and Arctic sea ice is continuing to melt precipitously.  Arctic sea ice is shrinking at a record pace both in extent . . .

. . . and in volume:

We’ve never seen anything like current conditions in the historical record.

As you can see, things are really heating up in the Arctic.

Looking back to 1880, the increase in global temperatures is striking.