by Dan Lashof, via NRDC’s Switchboard

NRDC released a report [this week] projecting that more than 150,000 additional Americans could die by the end of this century due to excessive heat caused by climate change. This startling conclusion is based on peer-reviewed scientific papers published recently by Dr. Larry Kalkstein and colleagues.

This is the kind of study that should make headlines around the country but is generally ignored when published only in scholarly journals. So NRDC is presenting the information in a more accessible manner, adding calculations of the cumulative additional death toll attributable to projected global warming by mid-century and century’s end (the report, including these additional calculations, was reviewed by Dr. Kalkstein to ensure that we have presented the information accurately)

The “Killer Summer Heat” report gives the results for all 40 cities analyzed in the original papers. The three with the highest number of projected heat-related deaths through the end of the century are: Louisville, KY (19,000 deaths); Detroit (18,000); and Cleveland (17,000). Other cities’ death tolls include:

• Baltimore: 2,900 deaths
• Boston: 5,700 deaths
• Chicago: 6,400 deaths
• Columbus: 6,000 deaths
• Denver: 3,500 deaths
• Los Angeles: 1,200 deaths
• Minneapolis: 7,500 deaths
• Philadelphia: 700 deaths
• Pittsburgh: 1,200 deaths
• Providence, R.I.: 2,000 deaths
• St. Louis: 5,600 deaths
• Washington, D.C.: 3000 deaths.

The projected deaths are based on the widely-used assumption that carbon pollution will steadily increase in the absence of effective new policies, more than doubling the levels seen today by the end of the century.

These findings bring home the fact that global climate change has a number of real life-and-death consequences in our local communities. One of which is that as carbon pollution continues to grow, climate change is only going to increase the number of dangerously hot days each summer, leading to a dramatic increase in the number of lives lost.

Read more

Jeff Masters, via Wunderblog

An unprecedented April heat wave brought a second day of sizzling temperatures to the Western U.S. yesterday, where temperatures ranging 20 – 30 degrees above normal have toppled numerous all-time April heat records.

All-time heat records for the month of April were set at 56 stations April 21 – 23, including at seven major cities. Image taken from wunderground’s new extremes page.

Nearly every weather station in the Inter-mountain West has broken, tied, or come within 1- 2 °F of their all-time record April heat record since Sunday. Most notably, the 113°F measured at Furnace Creek in Death Valley, California on Sunday, April 22 was tied for the hottest April temperature ever recorded in the U.S.

According to wunderground weather historian Christopher C. Burt, the hottest reliable April temperature ever measured in the U.S. was 113°F in Parker, Arizona in 1898. A 113°F reading was also taken at Catarina, Texas in April 1984. A hotter 118°F reading measured at Volcano Springs, CA in April 1898 is considered unreliable, since we don’t know much about the exposure conditions or if the thermometers were even in shelters at remote California desert stations back in the 1880s and 1890s. The previous hottest April day in Death Valley was 111°F. Yesterday, the high temperature in Death Valley “cooled off” to 110°F, merely the third highest April temperature ever measured there. The heat wave peaked Sunday and Monday, and temperatures will be closer to normal for the remainder of the week.

Read more

It’s official. This was “the warmest March on record” since records began in 1895, according to the National Oceanic and Atmospheric Administration.

How hot was it? It was so hot that NOAA reports “there were 15,272 warm temperature records broken (7,755 daytime records, 7,517 nighttime records).”

NOAA released some amazing charts and factoids yesterday:

• Hundreds of locations across the country broke their all-time March records. There were 21 instances of the nighttime temperatures being as warm, or warmer, than the existing record daytime temperature for a given date.
• A persistent weather pattern led to 25 states east of the Rockies having their warmest March on record. An additional 15 states had monthly temperatures ranking among their ten warmest.
• NOAA’s U.S. Climate Extremes Index, an index that tracks the highest 10 percent and lowest 10 percent of extremes in temperature, precipitation, drought and tropical cyclones, was 39 percent, nearly twice the long-term average and the highest value on record for the January-March period [see figure]:

U.S. Climate Extremes Index was the highest on record so far in 2012.

It was so hot that “March heat records crushed cold records by over 35 to 1“ and top scientists and meteorologists said that global warming loaded the dice. If you prefer sports metaphors, like a baseball player on steroids, our climate system is breaking records at an unnatural pace.

It was so hot that both ABC News and NBC ran excellent stories that connected the heat wave to global warming. Here is the ABC story, which spells out the health and food security “dangers” posed by “extreme climate risks”:

Here is the NBC News story, which labels manmade global warming, “the prime suspect” for the heat wave:

Read more

The final data is in for the unprecedented March heat wave that was “unmatched in recorded history” for the U.S. (and Canada).  New heat records swamped cold records by the stunning ratio of 35.3 to 1.

This ratio is almost off the charts, even with the brutally warm August we had, as this chart from Capital Climate shows.

For the year to date, new heat records are beating cold records by 22 to 1, which trumps the pace of the last decade by more than a factor of 10!

I like the statistical aggregation across the country, since it gets us beyond the oft-repeated point that you can’t pin any one record temperature on global warming. A 2009 analysis shows that the average ratio for the 2000s was 2.04-to-1, a sharp increase from previous decades. Lead author Dr. Gerald Meehl explained, “If temperatures were not warming, the number of record daily highs and lows being set each year would be approximately even.”

Meteorologist Jason Samenow points out just how extreme the heat wave was: “More than 7,700 daily record high temperatures were set (or tied, compared to just 287 record lows), in some cases by mind blowing margins and over multiple days. In several instances in the Great Lakes and Upper Midwest region, morning lows even bested record highs and high temperatures soared above mid-summer norms.”

Many of the countries leading climatologists and meteorologists have looked at the data and concluded that like a baseball player on steroids, our climate system is breaking records at an unnatural pace.

Weather Channel meteorologist Stu Ostro calls the current heat wave “surreal” and explained that “While natural factors are contributing to this warm spell, given the nature of it and its context with other extreme weather events and patterns in recent years there is a high probability that global warming is having an influence upon its extremity.”

Meteorologist Dr. Jeff Masters has said, “this is not the atmosphere I grew up with.” He published a detailed statistical analysis concluding, “It is highly unlikely the warmth of the current ‘Summer in March’ heat wave could have occurred unless the climate was warming.”

Climate Central pointed out that given the intensity, duration, and geographical breadth of the heat wave, “this may be an unprecedented event since modern U.S. weather records began in the late 19th century.” They interviewed several top scientists who explained global warming’s likely role in helping to make this extreme event so unique.

University of Utah’s Jim Steenburgh blogged that he is convinced global warming has played a role:

Welcome to the new climate in which heat waves are pushing farther outside the envelope of what has been observed previously during the historical record.  To quote Hansen et al. (2011), “Today’s extreme anomalies occur because of simultaneous contributions of specific weather patterns and global warming.”  I’m usually very cautious about linking weather events to global warming as there is considerable natural variability in the system, but these are jaw-dropping records and such events are more likely today than 60 years ago.

NBC News has a very good story about the cause of the extreme weather. Their chief environmental correspondent Ann Thompson interviews NOAA scientist, Dr. David Easterling:

Thompson:  But scientists say ping-ponging between weather extremes may be an indicator of a much bigger problem: the heat trapping gases of climate change

Easterling:  The warming that we’ve seen actually increases the chances, kind of loads the dice that were going to see these kinds of events more often.

Thompson: Dr. David Easterling of the National Oceanic and Atmospheric Administration is a co-author of United Nations report out this week that points to climate change as leading to extreme weather events since 1950.

Easterling:  The unusual warm days and nights, and to some extent heat waves, you can actually begin making that link between climate change and those events.

Watch it:

Since the science of attributing extreme events to global warming is still emerging, scientists still disagree to what extent a specific event like this heat wave is driven by global warming. But two of the  leading experts explain at RealClimate why even small shifts in average temperature mean “the probability for ‘outlandish’ heat records increases greatly due to global warming.” Furthermore, “the more outlandish a record is, the more would we suspect that non-linear feedbacks are at play – which could increase their likelihood even more.”

The really worrisome part is that we’ve only warmed about a degree and a half Fahrenheit in the past century.  We are on track to warm five times times that or more this century.

In short, we ain’t seen nothing yet!

IPCC (2001) graph illustrating how a shift and/or widening of a probability distribution of temperatures affects the probability of extremes. (Via RealClimate)

The full 592-page (!) IPCC extreme weather report is out. Like most Intergovernmental Panel on Climate Change reports it has some value for people who don’t follow the science closely, which is to say the overwhelming majority of the media and policymakers.

Of course, the TV media ignored the summary report in November, so we will have to see if they pay any attention to this one now that the United States has just been through the most extreme winter heat wave in our recorded history.

But as Kevin Trenberth, one of the world’s leading experts on the link between climate change and extreme weather, put it to me in an email:

I have seen the chapter on the physical climate and I found it quite disappointing…. I don’t think it adds to AR4 [IPCC Fourth Assessment] much.

I agree with Trenberth that if, for instance, you want a more up to date and straightforward discussion of the impact of climate change on precipitation, you should just read his 2011 paper, “Changes in precipitation with climate change” (online here).

Indeed, the actual scientific literature from 2011 is generally more useful than this report — see “NOAA Study Finds Human-Caused Climate Change Already a Major Factor in More Frequent Mediterranean Droughts” and Hansen et al: “Extreme Heat Waves … in Texas and Oklahoma in 2011 and Moscow in 2010 Were ‘Caused’ by Global Warming.”

It is, as I wrote when the summary came out in November, the report is “Another Blown Chance to Explain the Catastrophes Coming If We Keep Doing Nothing.”  I also wrote that the summary has a good chart that hints at dust-bowlification, but is mostly silent on warming’s gravest threat to humanity.

The full report has more on drought, but fails to clearly describe what the literature now suggests is coming if we stay anywhere near our current emissions path. In 2010, the National Center for Atmospheric Research did a far more valuable literature review and analysis of what we face, which makes clear we risk multiple, devastating global droughts even on moderate emissions path.

In the case of extreme weather, my guess is that decades from now, people will look back on the staggering growth in off-the-charts “outlandish” extreme events in the past few years and conclude that a regime change had occurred in the climate. That change is probably a combination of the sharp loss in summer/fall Arctic sea ice and the sharp increase in ocean heat content.

We’re only in the past year or so seen analyses that demonstrate the human fingerprint in these uber-extreme events, including the studies above and these two:

• Nature Climate Change: Strong Evidence Manmade ‘Unprecedented Heat And Rainfall Extremes Are Here … Causing Intense Human Suffering’
• Study Finds 80% Chance Russia’s 2010 July Heat Record Would Not Have Occurred Without Climate Warming

So rather than citing this timely, but already out-of-date IPCC report, let me just repost below an excellent new piece from RealClimate by the authors of those two studies, who have been doing some of the best recent work in this area.

Read more

March Heat Records Hit Incredible Ratio of 35 to 1 vs. Cold Records, Must-See Weather Channel Video Explains Link to Global Warming

Dr. Jeff Masters: A spring heat wave like no other in U.S. and Canadian history peaked in intensity yesterday, during its tenth day. Since record keeping began in the late 1800s, there have never been so many temperature records broken for spring warmth in a one-week period–and the margins by which some of the records were broken yesterday were truly astonishing. Wunderground’s weather historian, Christopher C. Burt, commented to me yesterday, “it’s almost like science fiction at this point.“

Yesterday, meteorologist Masters published a detailed statistical analysis that concluded, “It is highly unlikely the warmth of the current ‘Summer in March’ heat wave could have occurred unless the climate was warming.”

Based on satellite data, the map depicts temperatures from March 8–15 compared to the average of the same eight day period of March from 2000-2011. Image: NASA via Masters.

Among the stunning records set yesterday are:

• Pellston, MI: record high broken by 32°F
• Low temperatures beat the previous record high for the date at two stations
• Multiple Canadian cites break all-time April records for warmth in March

This off-the-charts event is just what scientists have been warning to expect if we kept spewing billions of tons of heat-trapping greenhouse gases into the air (see Hansen et al: “Extreme Heat Waves … in Texas and Oklahoma in 2011 and Moscow in 2010 Were ‘Caused’ by GlobalWarming”).

Meteorologists and science writers have been struggling to come up with words to describe this super-charged heat wave: “This is not the atmosphere I grew up with” and it’s “not just breaking but obliterating records” and “OFF THE SCALE WEIRD; even for Minnesota.” Climate Central wrote:

In fact, the broad geographic scope of this heat event, along with the margins by which records are being broken, the time of year this is occurring, and the duration of the event are all indications that this may be an unprecedented event since modern U.S. weather records began in the late 19th century.

Like a baseball player on steroids, our climate system is breaking records at an unnatural pace. Weather Channel meteorologist Stu Ostro calls the current heat wave “surreal” and explained that “While natural factors are contributing to this warm spell, given the nature of it and its context with other extreme weather events and patterns in recent years there is a high probability that global warming is having an influence upon its extremity.”

There is a must-see interview of Ostro on the Weather Channel’s website, in which he explains how “data and science” — see this big PDF – switched him from being a skeptic on climate change to someone who understands that humans are changing the climate now:

Weather Channel meteorologists are stunned by “the sheer number of daily record highs either tied or broken over the past two weeks” as they explain in their post, “Perspective: More than 4,000 Record Highs Set!“:

If you pull out your calculator and add the numbers up from March 9 to March 19, the total exceeds 4,300!! This speaks to the widespread nature and longevity of this warm spell….

Through March 21, International Falls, Minn., self-promoted as the “Icebox of the Nation”, has tied or broken daily record highs 11 of the past 12 days!

… Chicago, Ill. set record highs eight days in a row through Wednesday! In this streak, seven of the days have been in the 80s, including Wednesday’s astounding 87 degree high! The National Weather Service in Chicago recently called the warm spell “historic” and something that is unlikely to be matched in our lifetime.

We have entered the age of the exclamation point.

But the notion that this won’t be matched in our lifetime is to miss the impact global warming is having on heat records, according to the scientific literature.

Yes, this March U.S. heat records have been outnumbering cold records by a stunning amount – an incredible 35-to-1 – as this chart from Steve Scolnik at Capital Climate makes clear:

Read more

Speaking at a high-dollar Chicago fundraiser hosted by Oprah Winfrey as the city basked in June-like weather last week, President Barack Obama admitted to being “a little nervous” about global warming:

“We’ve had a good day,” Obama said. “It’s warm every place. It gets you a little nervous about what’s happening to global temperatures. But when it’s 75 degrees in Chicago in the beginning of March it gets you thinking…”

“Something’s wrong,” Oprah interjected.

“Yeah,” Obama said. “On other hand we really have enjoyed the nice weather.”

Instead of temperatures in the mid-40s, the historical average, Chicago is in a record-breaking streak of 80-degree weather. This “extreme and unprecedented” heat wave began last Wednesday and may continue through this Wednesday. “Before the heat wave, there had only been 10 March days on record that reached 80 degrees, and on average Chicago would see one 80 degree day in March every 14 years,” the Daily Herald reports. Most of the nation has been gripped by a record heat wave of weather as much as 30 to 40 degrees above normal. Global warming pollution is continuing to accumulate and heat the planet at a rapid pace.

2012 Heat Records Demolish Cold Records 14-to-1

It has been a summer to remember. In winter.

Like a baseball player on steroids, our climate system is breaking records at an unnatural pace. As Weather Channel meteorologist Stu Ostro says of the current heat wave:

This remarkable warmth is associated with a bulging ridge of high pressure aloft that is exceptionally strong and long-lasting for March. While natural factors are contributing to this warm spell, given the nature of it and its context with other extreme weather events and patterns in recent years there is a high probability that global warming is having an influence upon its extremity.

This year, U.S. heat records have been outnumbering cold records by a stunning amount — 14-to-1 (19-to-1 in March) – as this chart from Steve Scolnik at Capital Climate makes clear:

Monthly ratio of daily high temperature to low temperature records set in the U.S. for every month of 2011 and the first half of March, seasonal ratio for summer and fall 2011, winter 2011-2012 to date, and annual ratio for 2011 and 2012, data from NOAA.

I like the statistical aggregation across the country, since it gets us beyond the oft-repeated point that you can’t pin any one record temperature on global warming. If you want to know the historical ratios, see the 2009 analysis, “Record high temperatures far outpace record lows across U.S.,” which shows that the average ratio for the 2000s was 2.04-to-1, a sharp increase from previous decades. Gerald Meehl, the lead author and a senior scientist at the National Center for Atmospheric Research (NCAR), explained, “If temperatures were not warming, the number of record daily highs and lows being set each year would be approximately even.”

As Jason Samenow of the Capital Weather Gang notes, this week saw truly “Historic record warm weather“:

Temperatures more characteristic of June have broken hundreds of temperature records over the last several days and promise to continue into the next week in many areas. In some places, temperatures have been an eye-popping 30-40 degrees above normal, nearing or surpassing the warmest temperatures ever recorded so early in the season.

Since Sunday, an amazing 943 new record highs have been broken or tied across the U.S. compared to just 9 record lows

Record highs set Wednesday. Open circles indicate records were tied, circles with an x indicate records were broken.

This is not your father’s climate, as Ostro has documented at great length (see this big PDF):

In recent years I’ve documented hundreds of extreme and/or unusual weather events nationally and globally, but this one is even freaking me out with the nature of the air mass, clouds and downpours yesterday and today, and how the sky has looked so tropical, where I live in the Atlanta area – in mid-March. It’s surreal.

Unfortunately, it’s all too real — and just going to get worse and worse until we act to sharply reduce emissions of industrial carbon pollution.

Meteorologist Dr. Jeff Masters has done some great reporting on this heat wave, in part because he lives in Michigan, which just got slammed by “the earliest EF-3 or stronger tornado in Michigan history, going back to 1950.”

As Masters wrote Friday (emphasis in original):

As I stepped out of my front door into the pre-dawn darkness from my home near Ann Arbor, Michigan yesterday morning, I braced myself for the cold shock of a mid-March morning. It didn’t come. A warm, murky atmosphere, with temperatures in the upper fifties–30 degrees above normal–greeted me instead. Continuous flashes of heat lightning lit up the horizon, as the atmosphere crackled with the energy of distant thunderstorms. Beware the Ides of March, the air seemed to be saying. I looked up at the hazy stars above me, flashing in and out of sight as lightning lit up the sky, and thought, this is not the atmosphere I grew up with.

If we’re going to paraphrase Shakespeare, how about: Now is the winter of our discontent made glorious summer by global warming.

Here’s Masters today on “Summer in March continues for Midwest“:

Read more