- What would the world look like
if extreme climate change becomes reality?
Well, here's just one example.
If temperatures were to rise by three more degrees Celsius,
Shanghai, a city of 24 million people in China
will be wiped off the map.
And it's not just the only coastal city,
that's at risk of disappearing beneath rising sea levels.
Globally 2019 was the second hottest year on record.
Cities all throughout the world,
experienced record setting summer temperatures.
In June, 2019, temperatures in Churu, India,
exceeded 120 degrees Fahrenheit,
to the point that the government warned citizens
to avoid drinking coffee, tea, and alcohol
at a fear of overheating.
Heat waves are becoming more severe
and come in place due to climate change.
Projected to lead to deaths at the same rate
as all infectious diseases combined.
This map here, shows the increase in the severity
and prevalence of heat waves if the world follows
a moderate warming scenario.
By 2050, summertime highs of 95 degrees Fahrenheit,
or 35 degrees Celsius, will become the new normal,
in nearly 1000 cities triple the number of cities
that currently experience these sweltering temperatures.
But the irony is that cities are not just affected
by climate change, they're also causing it.
Cities consume between 60 and 80% of global energy resources
and account for approximately 70%
of global carbon dioxide emissions.
As we can see here in this map,
the light blue and the yellow areas
correspond to those with the highest
fossil fuel based carbon dioxide emissions,
and also correspond to major urban centers.
Aside from cities energy consumption, growing urban areas,
convert the planets green surfaces
to buildings and pavement, and these can absorb
more of the sun's energy,
than the natural grasslands and forests
that they've replaced, making urban areas hotter
than their surrounding environments.
This phenomenon is called the urban heat island effect.
Here in Singapore, downtown neighborhoods
can be as much as seven degrees Celsius
or 13 degrees Fahrenheit hotter,
than the rain forests that were once here.
While it's true that cities are contributing
to climate change, they're also key actors
in forging low carbon emission pathways.
In dense cities like New York city and Tokyo for instance,
the average resident is responsible
for over two tons of carbon dioxide emissions per capita.
This is less than a single passenger car emits
in a single year in the United States.
Cities around the world are stepping up
to tackle climate change, with ambitious policies
that often exceed the requirements of national governments.
Take Copenhagen for example,
it's committed to become carbon neutral by 2025
and Glasgow in Scotland also plans
to become carbon neutral by 2030.
Today, there are more than 10,000 cities
all around the world, that are committing
to their own ambitious climate actions,
plans that include emissions reduction targets,
clean energy and sustainable transit projects,
and also energy efficiency policies,
that can save people and cities,
money, energy, and emissions.
Recent analysis shows there's just 6,000 cities
combined with regions and companies,
are undertaking climate initiatives
that can reduce global emissions
by up to two gigatons of carbon dioxide equivalent in 2030.
That's roughly 4% of the world's total annual emissions
on top of what national governments have pledged.
And this is just the start, imagine what could happen
if 20,000 cities were to band together
to curb climate change.
While this potential for city's climate action
sounds really promising, cities must work to make sure
that these policies are implemented fairly and equitably.
Where you live in a city, your income, your race,
research is showing that these factors can determine
your access to environmental benefits
like green space and sustainable transit,
and they can also determine your share
of environmental burdens like air pollution
and climate change.
We observe these neighborhood level disparities,
particularly clearly, in the side-by-side images
of Los Angeles, comparing income on the left,
and tree cover on the right.
The darkest green neighborhood has an average annual income
of over a hundred thousand U.S. dollars per person.
And over 70% of it has tree cover.
The blue neighborhoods towards the bottom of the map,
only have a third of the income per person
and less than 5% tree cover, 70% versus five.
This disparity has real consequences.
Green spaces are often public spaces,
and they're known to be associated
with social and economic wellbeing.
They can also reduce crime and foster social cohesion.
Trees also can help to filter harmful air pollution
and provide evaporative cooling and shade
and relief for some of these high temperatures.
So not only are those poor neighborhoods
at a greater disadvantage from access to green space,
but they're also more vulnerable to air pollution
and climate change.
We can observe particularly pronounced disparities
and urban heat according to race.
Our latest research shows that 97%
of major urban areas in the United States,
are exposing black populations and people of color,
to a full degree Celsius higher of urban heat
than their white counterparts.
Take a look at this map of my hometown
of Greenville, South Carolina, unlike the name suggests
it is not green for everyone.
The hottest areas of the county shown on the map in red
correspond with the highest percentages
of black and poor populations.
And we're seeing similar patterns throughout cities,
all across the United States.
To address these inequalities,
cities are starting to strategize and develop plans,
that can ensure that climate benefits
are provided to all of their citizens equally.
Take Bogota, the capital city of Columbia for example,
it has one of the most extensive bike networks
in all of Latin America, connecting people to jobs,
education centers, and recreational opportunities.
A new bike highway project can allow
for around 42,000 daily bicycle trips, and potentially avoid
270,000 tons of greenhouse gas emissions.
In Africa, where many cities
lack universal access to electricity,
many grids are providing approximately 73 million households
with clean electricity.
So as we can see from these examples,
tackling climate change has to start in cities.
Many cities are starting to flip the script
on climate change, proving to be part of the solution
and not just the problem.
And bringing the kind of innovative solutions that we need
for a more just and sustainable world, thank you.