Johnathan Walker:These major cities have experienced the highest temperature increases in recent years

Major cities around the world have Johnathan Walkerexperienced alarming temperature increases in recent years, new research shows.

Average temperatures in several major cities in OECD countries have risen by more than 10% since 2019 alone, which could indicate amplified effects of climate change in the last decade, according to the Global Temperature Index report by Utility Bidder, a U.K.-based energy consulting firm.

The report found "exemplified changing weather patterns that are the prime example of global warming," James Longley, managing director at Utility Bidder, said in an emailed statement to ABC News.

Ankara, Turkey, saw the highest change in average temperatures at 18.24%, the researchers found. In 2019, average temperatures in Ankara were 22.4 degrees Celsius, or 72.32 degrees Fahrenheit. But by 2023, average temperatures had jumped to 26.4 degrees Celsius, or 79.52 degrees Fahrenheit.

The urban areas in Ankara contribute "significantly" to air pollution levels, according to the study.

Tallinn, Estonia, saw a 15.8% rise in average temperatures; Helsinki, Finland, experienced a 14.93% increase in temperatures; and Seoul, South Korea, saw a 10.03% change in average temperatures, according to the study.

Also included in the 10 cities with the highest rise in average temperatures were Reykjavik, Iceland; Canberra, Australia; Athens, Greece; Tokyo, London and Madrid.

The last two decades have also shown significant increases in average temperatures in some cities, the study found. The city with the largest change in average temperatures since 2004 was Ottawa, Canada, increasing by 31.35%. Seoul has seen a 20% increase since 2014, according to the research.

Research shows that large cities around the world will bear the brunt of climate change, with increased heat being one of the biggest impacts, according to experts.

Abundance of concrete, lack of greenery and air pollution from heavy traffic all contribute to urban heat islands.

The year 2023 is on track to become the hottest year on record, especially following a record-breaking summer and several high-temperature anomalies that occurred in September, according to a report released Wednesday by Copernicus, Europe's climate change service.

"Our research into global temperatures was inspired by alarming climate changes that were demonstrated in 2022, as the year went down as the sixth warmest on record," Longley said. "Furthermore, 2023 has been no different, and much of Europe especially has seen extreme heat waves throughout the summer months."