Superlatives such as “hottest”, “wettest” and “windiest” are becoming commonplace in news headlines, as freak weather events linked to climate change occur with increasing intensity and frequency.

In September, Bill de Blasio, Mayor of New York City and Sadiq Khan, Mayor of London co-authored an op-ed in the Guardian urging cities to stop their pension funds investing in fossil-fuel companies.

“It’s clear that what we think of now as freak weather in our cities is likely to become the new normal, and that climate change poses a huge threat to the futures of our children, and many generations to come,” they wrote.

This year, London experienced an unusually hot, dry summer, while New York had torrential rain.

A report by the University of Oxford’s Environmental Change Institute (ECI) in collaboration with the World Weather Attribution (WWA) network found that northern Europe’s record heatwave in 2018 was the result of human-caused climate change, warning that it was a sign of things to come.

Dr Friederike Otto, Deputy Director of the ECI, said in a media release: “What was once regarded as unusually warm weather will become commonplace – in some cases, it already has.”

Alongside rising global temperatures, extreme weather events have almost doubled over the last 30 years, with 797 recorded in 2016.

In the same year, the estimated economic costs attributed to climate change reached $129.4 billion, roughly double the figure a decade earlier.

Hurricane Katrina alone inflicted $108 billion in financial losses in 2005.

The rise in the use of fossil fuels has led to soaring costs of climate change
The rise in fossil fuels has led to soaring climate costs.
Image: Statista

According to a recently released Intergovernmental Panel on Climate Change (IPCC) report, the world is on target to exceed its “carbon budget” within the next 12 years. To hold global warming levels beneath the established 1.5°C goal over the long term requires global action to reach net-zero emissions within 25 years.

If warming does exceed the 1.5˚C target, the report states that carbon will need to be removed from the Earth’s atmosphere and stored, to cool the planet. There are a number of techniques to achieve this, such as bio-energy with carbon capture and storage (BECCS), afforestation and direct air capture and storage (DACS).

Deploying carbon removal at the scale required to cool the planet has never been tested and represents a step into the unknown. The surer path to a safe future is by cutting emissions.

The mayors are taking steps to divest their respective city pensions funds from fossil fuels and announced a new global initiative on divestment and sustainable investment to help other cities do the same.

New York City mayor Bill De Blasio is moving to withdraw $5 billion from carbon-based energy investments. New York City aims to be fossil-fuel free within five years and has invested $2.7 billion in initiatives that promote energy-efficiency, save public money and reduce emissions. For example, the city has introduced over 1,200 electric vehicles and 500 charging stations.

 New York City Mayor Bill de Blasio speaking at the World Economic Forum’s Sustainable Development Impact Summit.
New York City Mayor Bill de Blasio.
Image: Ben Hider

On the other side of the Atlantic, London has withdrawn £700,000 ($914,000) from carbon-based energy investments so far this year. Less than 2% of the city’s £5.5 billion ($7.1 billion) pension fund remains tied to fossil fuel extraction, but Mayor Sadiq Khan has announced plans to fully divest the fund.

The UK capital recently launched the Mayor’s Energy Efficiency Fund, investing £500 million ($653 million) to promote greener, more energy-efficient hospitals, museums, offices, libraries, social housing and universities.

The mayors’ message is clear: they want cities to invest in a cleaner future.

“We believe that ending institutional investment in companies that extract fossil fuels and contribute directly to climate change can help send a very powerful message that renewables and low-carbon options are the future,” they wrote.

“If we want to fund the scale of transformation the world needs, we must foster sustainable investment and use the power of institutional investors, such as pension funds.”