Carbon intensity vs absolute emissions

World leaders are set to meet in New York in two
weeks time to discuss how best to address global climate change.
High on the agenda will be working out how to wean countries off
cheap fossil fuels while keeping their economies afloat.

A new
by consultancy PwC shows that for all the
politicians’ promises
, the global economy is still far from
being “green”. Current efforts to incentivise cleaner economic
growth are falling short of those needed to avoid dangerous global
warming, it says.

Emissions ‘cuts’

Global carbon intensity – annual emissions divided by GDP – has

fallen by 1.2 per cent
, the report shows. But that somewhat
masks what’s actually happening to global emissions.

Carbon intensity is a measure of how efficiently countries use
their polluting energy resources, such as coal, oil and gas.

So long as a country’s energy sector emissions grow at a slower
rate than its GDP, the carbon intensity of its economy falls. But
although some countries are ramping up renewables, many still rely
on burning large amounts of fossil fuels to drive economic

As a consequence, global emissions have rapidly risen despite
great progress in reducing the energy sector’s carbon intensity, as
this chart shows:

Source: Emissions
from the US Energy Information Administration, GDP
from the World Bank. Graph by Carbon Brief.

As the global economy has grown over the past 25 years, global
emissions have risen rapidly. That’s despite many countries
improving their energy efficiency and switching from coal to
less-polluting gas power.

Unless countries get more ambitious about restricting fossil
fuel use, this trend is likely to continue. That’s why the slight
fall in global carbon intensity isn’t particularly good news.

Keeping to two degrees

At this rate, the world could be set to warm by as much as four
degrees above pre-industrial levels by 2100, PwC says.

Politicians have agreed to try and curb warming by two degrees.
For that to happen, countries can’t emit more than
around one billion tonnes of carbon dioxide
, according to the
Intergovernmental Panel on Climate Change’s (IPCC) latest report.
At current rates, the world is likely to have emitted that amount
by 2034, PwC says.

To keep within two degrees, it estimates that global carbon
intensity must fall by 6.2 per cent a year, with the energy sector
being totally decarbonised by the end of the century:


Source: PwC’s
6th Low Carbon Economy Index Report
. Discrepancy from starting
point compared to graph above is due to using different datasets.
PwC does not provide raw data with its report.

That will be a major challenge. Many developing economies,
including India and China, are growing largely thanks to the
availability of cheap, high carbon, fuels such as coal. Even
countries making better progress at cutting carbon intensity, such
the UK
, continue to rely on fossil fuels for much of their

PwC’s report shows just how tough government’s are
finding it to decouple their economies from high carbon energy
systems. For all politicians’ talk of
promoting “green growth”
, the data shows
current policies are largely failing to deliver.