>> >>AMITA: SCORCHING TEMPERATURES HAVE PLAGUED SAN DIEGANS FOR THE PAST TWO WEEKS.
WHILE THERE'S A BRIEF BREAK IN STORE, EXPECT THE HEAT TO MAKE A COME BACK BY WEEK'S END.
RECORD HOT WEATHER HAS LEFT MANY WONDERING IF CLIMATE CHANGE IS GEGHT MORE PROFOUND.
JOINING ME ARE METEOROLOGIST OF ALEX TARDY AND DANIEL CAYAN WHO IS A RESEARCH METEOROLOGIST
FOR THE SCRIPPS INSTITUTION OF OCEANOGRAPHY.
ALEX, LAST MONTH WAS THE HOTTEST MONTH ON RECORD IN THE UNITED STATES.
HOW HOT DID IT GET AND DID THAT RECORD ACTUALLY HOLD TRUE FOR SAN DIEGO?
>> >>ALEX TARDY: IT WAS INCREDIBLY.
THE MONTH OF JULY WE LOOK THAT WHOLE JUNE WAS THE HOTTEST WE'VE SEEN SINCE THE 30S.
AND TO COMPOUND THAT, WE'RE SEEING THE WORST DROUGHT ACROSS THE UNITED STATES SINCE THE
50S.
SO THE TWO KIND OF GO HAND IN HAND.
FOR US IN SAN DIEGO, WE'VE BEEN SPARED BY SOME OF THIS EXTREME HEAT UNTIL RECENTLY.
JULY DID NOT TURN OUT TO BE A RECORD HOT MONTH FOR REALLY ANYWHERE IN SOUTH WEST CALIFORNIA.
AUGUST, THOUGH, IS ON PACE, ESPECIALLY FOR OUR DESERTS LIKE PALM SPRINGS, TO BREAK SOME
RECORDS HERE IN SAN DIEGO, WE'RE RUNNING A DEGREE OR TWO ABOVE NORMAL AND I'M SURE MOST
PEOPLE HAVE NOTICED IT.
>> >>AMITA: AND WHAT IS THE FORECAST FOR THE REST OF THE SUMMER?
>> >>ALEX TARDY: FORECAST IS WE'RE PROBABLY GOING TO DEAL AT LEAST FOR THE NEXT WEEK WITH
ANOTHER HEAT WAVE.
WE'LL HAVE A LITTLE BIT OF A RELIEF THIS WEEK.
WHEN WE GET INTO SEPTEMBER, PROBABLY ONE MORE GOOD HEAT WAVE, NOT AS SEVERE AS AUGUST.
AND WE'LL HOLD OUR BREATH THAT WE DON'T HAVE A LOT OF WIND DURING OUR NORMAL FIRE WEATHER
SEASON.
>> >>AMITA: DAN, A LOT OF US SEEM TO THINK OF CLIMATE CHANGE AS AN EVENT IN THE FUTURE,
BUT WE'RE SEEING DROUGHTS WITH MORE FREQUENCY.
WE'RE SEEING HEAT WAVES WITH MORE FREQUENCY.
ARE THE TWO LINKED?
ARE WE NOW EXPERIENCING CLIMATE CHANGE?
>> >>DANIEL CAYAN: WE UNDOUBTEDLY R.THE CHANGE IN THE ATMOSPHERE, CHANGE GREEN HOUSE GAS
CONCENTRATIONS HAVE INCREASED MARKEDLY FROM PRE INDUSTRIAL LEVELS.
BUT WE'RE STILL IN THE EARLY PHASE OF THE CLIMATE CHANGE PHENOMENON.
IN PARTICULAR, THIS EVENT THAT HAS SET UPON US THE LAST WEEK OR SO, IT'S CERTAINLY NOT
THE ONLY ONE WE'VE EVER SEEN AS ALEX CAN TESTIFY AND WE'VE SEEN IN 2006, FOR EXAMPLE WE HAD
A REMARKABLE HEAT WAVE HERE IN CALIFORNIA.
BUT IT'S LIKELY THAT THE CLIMATE WARMING FROM GREEN HOUSE GASES PLAYING AN INCREMENTAL ROLE.
>> >>AMITA: IS IT HAPPENING FASTER THAN WE THOUGHT?
>> >>DANIEL CAYAN: I WOULD SAY THAT THIS IS PROBABLY ON PAR WITH WHAT CLIMATE MODELS ARE
PROJECTING.
THERE'S A NUMBER OF CLIMATE MODELS WE LOOK AT AN INTERNATIONAL SUITE OF MODELS THESE
DAYS AND WE LOOK AT THEM UNDER A VARIETY OF SCENARIOS.
THEY ARE PROJECTING ON AVERAGE TEMPERATURES TO INCREASE BY AT LEAST TWO DEGREES FARENHEIT
BY THE MIDDLE PART OF THE CENTURY AND AS HIGH AS FIVE DEGREES.
THAT'S FOR AN ANNUAL AVERAGE.
IF YOU COMPOUND THAT WITH ONE OF THESE HEAT WAVES ALEX DESCRIBED, THAT'S GOING TO MAKE
THINGS MORE INTENSE, PROBABLY MORE DURABLE, LONGER LASTING.
SO IT'S LIKELY THAT WHAT WE'RE SEEING IS THE PROGRESSION OF EVENTS TO ESSENTIALLY A CLIMATE
WE HAVE NOT EXPERIENCED IN OUR HISTORICAL PAST.
>> >>AMITA: THAT MEANS WE'LL SEE MORE FREQUENCY OF THESE HEAT WAVES AND OF DROUGHTS.
WHAT ABOUT IN THE SHORT TERM, WHAT'S COMING UP THIS WINTER?
WHERE DO THINGS STAT STAND WITH LA NI„A, OR EL NI„O, I SHOULD SAY.
>> >>ALEX TARDY: YEAH, EITHER ONE OF THOSE.
IT LOOKS LIKE THE CURRENT PROJECTIONS ARE GOING TO PUT US INTO AN EL NINO FOR THIS WINTER,
LATE FALL.
WE'LL PROBABLY HAVE A HIGHER PROBABILITY OF AT LEAST NORMAL PRECIPITATION FOR SOUTH WEST
CALIFORNIA.
IF THE EL NI„O BECOME AS LITEDDAL BIT STRONGER, THEN WE HAVE A BETTER CHANCE OF SEEING ABOVE
NORMAL PRECIPITATION.
THAT'S A GOOD THING BECAUSE RIGHT NOW WE'RE DOING FINE BECAUSE OF THE WET 2010, 2011 RESERVOIR
SUPPLY IS HIGH, BUT ANOTHER YEAR OF DRY WE SAW THIS PAST WINTER WOULD COMPLICATE THINGS
SIGNIFICANTLY.
SO AT LEAST NORMAL PRECIPITATION IS WHAT WE'RE THINKING NOW AND HIGH CONFIDENCE WE'RE GOING
INTO AN EL NI„O. EL NI„O IS THE WARMING OF THE PACIFIC OCEAN
IN THE EQUATORIAL REGION.
>> >>AMITA: DAN, IN ABOUT 10 SECONDS HOW WOULD YOU CHARACTERIZE POLITICAL LEADERSHIP ON THIS
SUBJECT OF CLIMATE CHANGE?
>> >>DANIEL CAYAN: UH, I WOULD SAY WE HAVE A WAYS TO GO IN TERMS OF SHOWING LEADERSHIP
AND BUILDING OUR WAY OUT OF THIS SITUATION.
>> >>AMITA: DAN, ALEX, THANK YOU FOR JOINING US TODAY.