record temperatures and unprecedented
wildfires
devastating storms
flooding so severe and unexpected that
new york is brought to a standstill
[Applause]
extreme weather seems to be sweeping the
world
some climate activists claim it's proof
our way of life is about to end
others deny there's anything unusual
happening so what is going on
stick with us as we find out what's
causing so much extreme weather and will
it get worse
here on elder fox
over the last year or two news reports
have been full of shocking images
unprecedented snow in texas droughts in
kenya that have put 2 million lives at
risk of starvation
massive flooding from india to germany
and crippling dust storms in china
across europe from helsinki to siberia
to italy temperature records have been
smashed
wildfires have raged out of control from
california and oregon to greece
a record number of hurricanes and
cyclones have caused destruction from
the united states to indonesia
perhaps most shocking of all the
incredible heat dome across north
america that saw temperatures in canada
and the northern united states soar past
50 degrees celsius something that
scientists dubbed impossible
is it all just coincidence
does it just seem like the weather is
becoming more extreme and surely so many
different types of extreme weather
events can't all have the same cause
but unbelievably most scientists now
agree the weather is becoming more
violent and destructive and most of
these events could be explained by one
factor
a seemingly tiny rise in average global
temperatures could be the cause of much
of the mayhem
but why
and how
as this animation based on the actual
data shows there's no doubt that the
earth has been warming over the past 150
years or so
cooler than average temperatures are
shown in blue warmer than average in red
so the change since 1880 and especially
since the 1990s is frighteningly clear
over this period the average global rise
in land and sea temperatures is around 1
degrees celsius
[Music]
that may sound like nothing but over
such a short period of time it's enough
to have a big impact on the entire
planet including our weather
but how could rising temperatures
explain all the extreme weather events
that have been taking place
it's easy to understand that heat could
lead to more droughts or wildfires
but how could it explain the worst
snowfall in madrid in the last 50 years
were the unprecedented winter storms in
texas that killed over 200 people in
2021
and why would a simple rise in
temperature make hurricanes and cyclones
more devastating
it may seem impossible but earth's
weather is an incredibly complex
balancing act of pressure temperature
and moisture differences around the
globe
a small change in one part of the world
can have a major impact on the other
side of the planet
at its simplest rising temperatures
especially rising sea temperatures can
make many weather events more dynamic
and powerful
because more heat in the system means
more energy available so a higher chance
of more extreme and damaging weather
that alone could explain why 2020 was a
record year for hurricanes and why they
seem to be intensifying more quickly too
the moisture from warmer seas provides
more fuel to create more storms of
greater power
but our weather is also regulated by air
and sea currents such as the jet stream
a current of strong winds high in the
atmosphere
it both develops and moves areas of low
pressure around the globe
along with similar currents it keeps the
weather working
now though it seems rising temperatures
might be having an effect on that
delicate global circulation there is new
evidence that circulation may be
changing and slowing down
normal weather patterns are becoming
disrupted with a rise in so-called
blocking events
increasingly storms and other weather
events are becoming stuck in one place
making the effects more prolonged and
destructive
it happened when hurricane harvey
stalled over southeast texas in 2017
leading to an incredible 60 inches of
rain something that one scientist
described as biblical using existing
climate models an event of that
magnitude should only happen once every
nine thousand years
but mit researchers calculate it's now
six times more likely to occur than it
was even 20 years ago
a similar blocking pattern also
contributed to the heat dome that killed
at least 500 people across canada and
the northern united states
due to changes in the jet stream an area
of high pressure became stuck the warm
air under it couldn't escape so it just
became hotter and hotter the result was
a heat wave beyond anything ever
experienced in the region smashing
temperature records and leading to
hundreds of deaths
but in just the same way blocking events
can cause extreme cold winter storms can
also slow and stall
and changes in air currents can create
freezing conditions in areas that would
normally be more temperate as has
happened recently from texas to southern
europe
it seems illogical but by disrupting
normal weather patterns warmer average
global temperatures really could lead to
more extreme cold weather too
even in areas where it's least expected
and the really bad news is at present
the rise in global temperatures seems to
be accelerating 18 of the 19 warmest
years since records began have occurred
since 2001.
the rise in average temperatures since
pre-industrial times is now widely
expected to hit 1.5 degrees celsius
within a few years and the increase in
extreme weather could be helping to
drive that acceleration
right now warming isn't spread equally
over the globe with arctic areas
particularly affected
in 2020 as temperature records were
broken in many northern areas ice levels
in the arctic reached a near record
minimum
this released thousands of tons of water
into the oceans
alongside that glaciers in many northern
regions such as greenland are melting
fast too
leading to rising sea levels and more
extreme flooding in coastal areas
warmer sea temperatures globally also
mean the ice is less likely to reform in
winter a study by the european space
agency's climate office suggests the
arctic seas could be largely ice free by
2050 with potentially serious
implications for the climate
at the same time
thousands of square miles of frozen
tundra across siberia were thawing and
even burning this releases carbon
dioxide that has been locked away for
thousands of years back into the
atmosphere
which can then lead to more warming more
melting and so the cycle continues to
accelerate
there are similar things happening
worldwide california and australia both
saw record wildfires in 2020
the smoke from those fires can cause
further warming of the atmosphere and
air pollution that can spread for
thousands of miles which again means
more heating more drought more wildfires
it becomes a vicious cycle and
scientists fear will soon hit a tipping
point after which it may be impossible
to stop temperatures from rising by as
much as 4 or 5 degrees celsius but why
are temperatures rising
could it just be a natural phenomenon
we know that all through its history
earth has gone through periods of
warming and cooling
average global temperatures have been
warmer in the past than they are now
it's also well established that natural
climate patterns such as those nicknamed
el nino and la nina can affect weather
right around the world
changes in solar activity also affect
our climate
but all of those factors could only
account for a small amount of the
changes we're seeing
what is happening now doesn't seem to
follow any of the natural patterns that
the planet has experienced in the past
instead the vast majority of scientists
put the current warming down to one
thing
human activity
to quote a joint statement from 18
different scientific bodies based on the
extensive scientific evidence it is
extremely likely that human activities
especially emissions of greenhouse gases
are the dominant cause of the observed
warming since the mid 20th century there
is no alternative explanation supported
by convincing
evidence whether you believe that or not
there's no question temperatures are
rising and earth's climate is a finely
balanced mechanism
knock it out of alignment by just a
small amount and things can change
frighteningly quick
once change begins it can be very hard
to stop
it might already be too late to reverse
the effects we're seeing on our weather
and the costs of those changes is
already huge economically on wildlife
and human life
according to a recent report by the
world meteorological organization the
number of extreme weather events has
increased by a factor of five over just
the last 50 years
weather climate and water hazards
accounted for 50 percent of all
disasters and 45 percent of all reported
deaths
an average of 202 million dollars in
damage was caused every day by weather
events
hurricane harvey alone cost the u.s an
estimated 96.9 billion dollars in
economic losses
with extreme weather events likely to
become even more common that just might
be a small taste of what could be in
store for us all
[Music]
thanks for watching elder fox
if you enjoyed this video click here to
see the next one
remember to like share and subscribe to
keep up to date with the latest
discoveries