This video was made in collaboration with the National Center for Science Education
It’s the beginning of summertime high in the alpine meadows of the Colorado Rocky Mountains,
and colorful displays of native wildflowers are just starting to bloom. But if you listen
carefully, you might notice something a little off. The usual buzz of bees foraging for food
has to yet begin.
In this particular alpine ecosystem, climate change has reduced the annual winter snowpack,
and warmer spring temperatures accelerate snowmelt. This extends the growing season
for plants - meaning that flowers bloom earlier than in decades past - but also makes them
more vulnerable to drought. But for the bees, warming temperatures have had a different
effect - instead of emerging earlier, as the plants did, many are now found higher up the
mountain, where the temperatures are cooler and better suited for bee activity. Bees and
plants are now experiencing less synchrony - they’re less often in the same place at
the same time. As a result, bee’s are struggling to find food and populations have declined.
This disruption of closely evolved symbiotic, or mutually beneficial, relationships - like
bees and flowering plants - can potentially lead to the extinction of other related organisms,
such as small mammals who dine on alpine plants, because, ultimately, the fate of multiple
species in this ecosystem are closely intertwined. But the bees and flowers in the alpine meadows
of the Colorado Rockies are just a small snapshot of what’s to come. As the climate changes
and the world warms we are beginning to witness a global trend of decreasing biodiversity.
At its simplest, biodiversity is a measure of the variety and variability of life. Measures
of biodiversity include the total number of species in an ecosystem, the number of endemic,
or geographically unique, species, and the genetic diversity of a single species in the
ecosystem. Though there are many ways to measure biodiversity, these all seek to capture the
distribution of the variation of life we see around us. And as we’ve just seen with bees
in Colorado, climate change, along with habitat fragmentation, urbanization, and pollution,
are having huge impacts on global biodiversity. Today we are going to explore some ecosystems
whose biodiversity has been impacted by climate change.
Meet the Hawaiian honeycreeper, a unique family of birds endemic to the Hawaiian islands.
The 51 species of honeycreeper were once abundant throughout the islands, but today almost half
are extinct. A combination of invasive species and human land-use changes have decimated
the honeycreeper’s lower-altitude habitats, while climate change in Hawaii keeps forcing
the birds to roost higher and higher, into much more limited space. Essentially, the
honeycreeper is running out of room to live. It is predicted that in the next 100 years,
all remaining species of this bird will be extinct.
But this loss of biodiversity isn’t specific to Hawaii, it’s occurring on islands around
the world. Islands are not only home to many endemic ecosystems, but they also represent
excellent case studies for understanding how climate change might affect worldwide biodiversity.
Islands have limited space, exacerbated by climate change-induced sea-level rise, which
makes it harder for species like the honeycreeper to change geographical ranges. In Polynesia,
the International Union for the Conservation of Nature estimates that 305 species may be
vulnerable to the direct effects of climate change, through restriction of their ranges,
increases in temperatures, and the effects of fires and other extreme weather events.
Currently, island species go extinct at a much higher rate than mainland species, with
that number expected to go up as climate change becomes more pronounced.
We are seeing the effects of climate change on biodiversity now and will continue to see
them worsen in the future. The record-breaking high temperatures and severe drought in Australia
from 2019-2020 is yet another example. This extreme weather brought an onslaught of unusually
massive bushfires across the country. Millions of hectares were burned, decimating an estimated
half a billion mammals, birds, reptiles, and insects, clearly decreasing the biodiversity
of Australia. The fires also destroyed mature trees that provide shelter for many organisms;
reduced the amount of food available in burnt areas, and decreased biodiversity by limiting
which plants are able to recover from the devastated areas. Biodiversity is like a network
of interactions directly and indirectly dependent on one another and climate change will only
disrupt these networks even more in the future.
Biodiversity hotspots, like Australia, are irreplaceable in that they contain endemic
plants and animals that can’t be found anywhere else. These hot spots also support human populations
that are often dependent on interactions with the land through subsistence agriculture and
foraging. Decreasing biodiversity due to anthropogenic-induced climate change threatens their survival. The
United Nations Department of Economic and Social Affairs states, “Climate change poses
threats and dangers to the survival of Indigenous communities worldwide, even though Indigenous
peoples contribute the least to greenhouse gas emissions.” In the face of these challenges,
the report points out, “Many Pacific Islander communities are also building new infrastructure
and creating relocation plans. For example, the Native Hawaiian people are some of the
global leaders in climate change policy, planning, and adaptation. In 2018, the Hawai’i legislature
passed two bills pledging to make the state carbon neutral by 2045.”
We can all draw inspiration from the leadership of indigenous communities in addressing climate
change by taking steps to help preserve biodiversity. This can include supporting conservation efforts,
such as preserving critical habitat and restoring degraded ecosystems or it can mean connecting
with environmental centers, conservation societies, and environmental advocacy groups in your
community. Ultimately, efforts to reduce the rate of global warming are our best bet for
preserving earth’s biodiversity. From advocating for environmental policies in national and
state government, to working with habitat restoration groups, or even reducing your
own carbon footprint, local actions that you take today can have a huge impact on maintaining
the diversity- of bees and other animals - worldwide.
Hey everyone, Charlie here. If you've been watching Our Changing Climate for a while
or just stumbled across this video and are wondering how you can help me make more videos,
then consider supporting the show on Patreon. As an OCC patron, you’ll gain early access
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each month my supporters vote on an environmental group that I then donate a portion of my monthly
revenue to. So if you want to support the channel or are feeling generous, head over
to patreon.com/ourchangingclimate and become an OCC patron. The script for this video was
written by two National Center for Science Education Graduate Student Outreach Fellows,
Cat and DJ. It was awesome to work with them and I hope you liked the video as much as
I enjoyed making it. Thanks for watching and I will see you in two weeks.