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Sandy Tops List of 2012 Extreme Weather & Climate Events

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No. 3  Turning Up the Heat: Hottest Year on Record in the Lower 48 States

2012 will go down in history as the hottest year on record in the continental U.S., pushing 1998 into second place. In line with the global warming trend spurred by steadily rising carbon emissions, seven of the top 10 warmest years in the 48 states have occurred in the past 15 years.

Like so much recent record-breaking weather, 2012 isn’t just going to top the previous record, 2012 is looking to smash it, by more than 1°F. In mid-December, Climate Central projected that 2012 average temperature for the continental U.S. at 55.34°F compared to the previous record set in 1998 of 54.32°F. For perspective, 1°F is one-quarter of the difference between the coldest and warmest years ever recorded in the U.S.

Average annual temperature in contiguous U.S. from 1895 to 2012.
Click on the image for a larger version.

The country endured many unusually long-lasting and severe heat waves as temperatures spiked in March, and never fell below average. March was the warmest such month on record in the lower 48 states, exceeding the average monthly temperature by 7°F. After the March heat wave, the contiguous U.S. recorded its warmest Spring, largest seasonal departure from average, third-warmest summer, and warmest 12-month period, all new marks since records began in 1895.

The average springtime temperature in the lower 48 was so far above the 1901-2000 average — 5.2°F, to be exact — that the country set a record for the largest temperature departure for any season on record.

The dominance of mild conditions is starkly apparent when looking at the balance between daily record highs set or tied this year and daily record lows. During 2012, there were 33,753 daily record-high temperatures set or tied, compared to just 6,303 daily record-low temperature records. That means that for every five daily record highs, there was just one daily record low set or tied.

When taking into account record-warm overnight low temperatures as well as record-cold overnight low temperatures, the ratio was closer to 4-to-1. No matter how you slice it, warm temperatures absolutely dominated the U.S. weather in 2012.

As the climate has warmed during the past several decades, there has been a growing imbalance between record daily high temperatures in the contiguous U.S. and record daily lows. A study published in 2009 found that rather than a 1-to-1 ratio, as would be expected if the climate were not warming, the ratio has been closer to 2-to-1 in favor of warm temperature records during the past decade (2000-2009). This finding cannot be explained by natural climate variability alone, the study found, and is instead consistent with global warming.

The study used computer models to project how the records ratios might shift in future decades as the amount of greenhouse gases in the air continues to increase. The results showed that the ratio of daily record highs to daily record lows in the lower 48 states could soar to 20-to-1 by mid-century, and 50-to-1 by 2100.

Related Content 
Ongoing Coverage of 2012 Summer Heat Waves 
2012 Record Temperatures: Which States Led the Nation 
July Sizzles, Records Fall: Warmest Month on Record 
High Times: More 2012 Record Highs than All of Last Year 
2012 Heat Wave is Historic, if not Unprecedented 
Heat Wave Peaks After Breaking Thousands of Records

(Read each of the Top 10 events by following the page links below)

Page 4 of 11 pages « First < 2 3 4 5 6 > Last »


By Emma H. (Rockwood, Ontario, Canada)
on December 31st, 2012

If the first step to survive climate change is interest, the second is knowledge. Which makes it worth considering that the place where we gain much of our common knowledge is school.  Unfortunately for the issue of climate change, school is focused on the economy, on creating good participants in the global marketplace, as well as good consumers who measure their success by their material gains.  And who are encouraged to spend more than they earn through easy credit and resulting debt.

What would it take for Americans to demand that education contribute to creating a sustainable future? It’s not a simple or easy change from our current educational aspirations.  But it’s one that might make it possible to work together and make the profound changes that will be needed to, first of all, lessen fossil fuel use, and then live well with less of the energy and petroleum products we’re addicted to.

We can create more local economies, regain lost skills, build local renewable energy systems, build local businesses, improve batteries needed to store power from intermittent wind and solar sources, begin a transition to a less lethal kind of culture.  We need to do it ourselves because our leaders are far too swayed by powerful fossil fuel and financial industries who invest hugely in maintaining the status quo.  But every decision we make, individually and collectively, can move the future to a new place.  Every product we buy comes from a company with policies we can support or reject.  Every mile we drive generates carbon dioxide - every mile we walk or bike - or don’t travel - doesn’t.  Local food and good insulation save energy, organic food doesn’t use fossil-fuel based chemicals (pesticides, fertilizers, hericides).  Growing food and making things and playing music are highly satisfying skills that we have been educated to give up so we need to buy them “in the marketplace.”  But we could take them back. 

If we don’t begin to think more self-sufficiently, and with more awareness of the connections betwween fossil fuels and climate change, we’ll continue to see the weather become more violent, food prices rise, the cost of living soar, and “homeland security” come to mean the degree of climate stability we need. 

We were only able to become an agricultural society because of the last ten thousand years of stable climate.  If we continue to exacerbate climate change, we risk losing nothing less than the basis of civilization.  Education may be our only chance to bring about a large-scale turnaround. It can only happen if we work - hard - to make it happen.

We need to make our schools places of learning how to become a sustainable civilization.  If this is a new idea to you, do some browsing on “sustainability education.”

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