2023 – A historic climatic year, as WMO Secretary-General Taalas successfully completes his mandate

22 December 2023

Geneva (WMO) – Professor Petteri Taalas is completing his eight-year mandate as Secretary-General of the World Meteorological Organization – a period which coincided with accelerating climate change impacts and more extreme weather, highlighting a growing need for better weather and climate services and early warnings.

Key messages
  • Key climate indicators and impacts worsen
  • Greenhouse gas levels continue to increase
  • Huge socio-economic climate-related impacts highlight need for Early Warnings for All
  • WMO global leadership and collaborative expertise and services more vital than ever

Prof. Taalas was at the helm of WMO for the warmest eight-year period in recorded history.
He became WMO Secretary-General in 2016, which was the warmest year on record at the time, because of a combination of climate change and very strong El Niño conditions. He concludes his mandate in the knowledge that 2023 will break that temperature record and make climate history for all the wrong reasons as the climate continues to warm.

“The expertise and services of WMO and the scientific community have never been more necessary to tackle climate change, which is represents humanity’s biggest challenge,” says Prof. Taalas.

“I leave WMO with a request to world leaders. Please pay attention to the scientific evidence and listen to the United Nations which is committed to promoting the welfare of citizens worldwide. We are proud of our mandate but we need your support to succeed,” he says.

The agreement at COP28 in Dubai is historic in that – for the first time – it recognizes the need to transition away from fossil fuels. This is an important step in the right direction but not the final goal. We urgently need to reduce our production and consumption of fossil fuels and speed up the transition to renewable energy. Time is running out,” said Prof. Taalas.

Prof. Celeste Saulo of Argentina succeeds Prof. Taalas, who will resume his position as Director-General of the Finnish Meteorological Institute.

Accelerating climate change

At the start of Prof. Taalas term in office in 2016, the global mean abundance of carbon dioxide in the atmosphere was 403.6 parts per million. It was 417.9 parts per million in 2022 – the most recent year for global statistics – and continued to rise in 2023.

Sea level rise accelerated, sea ice reached new lows and ocean heat and acidification increased. The intensity and frequency of heatwaves increased – with most changes being attributed to climate change – and heavy rainfall events became more intense with devastating consequences.

In the last two years of his term – 2022 and 2023 – Swiss glaciers lost an astonishing 10 percent of their volume. They may be gone by the end of the century.

According to WMO’s provisional State of the Global Climate report, released for COP28, the year until the end of October was about 1.40 degrees Celsius (with a margin of uncertainty of ±0.12°C ) above the pre-industrial 1850-1900 baseline. It was also the warmest November on record. WMO will issue its final consolidated temperature figures, based on six international datasets, in January. Land and sea surface temperatures reached record highs in 2023.

2023 saw many high-impact weather events which up-ended people’s lives and caused massive socio-economic costs on every inhabited continent.

Intense and extended heatwaves gripped dozens of countries, harming health, ecosystems and economies and triggering massive wildfires. Drought turned to deluge and displaced many thousands in the Greater Horn of Africa, whilst deadly flooding in Libya killed more than 10,000 people. Drought affected many parts of South America, impacting transport and energy. Rapidly intensifying tropical cyclones caused devastation in coastal communities all over the world.

A map of the world.

Early Warnings for All

The increasing number of extreme weather events and mounting economic losses highlighted the need for the creation of the Early warning for all initiative under the auspices of the UN Secretary General Antonio Guterres and co-led by Prof Taalas and SRSG of UNDRR Mami Mizutori, with support from key UN and international partners .

“In the past eight years we have saved countless lives thanks to early warnings and better risk-informed disaster management. The Early Warnings For All initiative aims to ensure that everyone on Earth is protected by life-saving early warnings by the end of 2027 and we are determined to succeed,” he says.

There are other grounds for optimism, says Prof. Taalas.

“More fundamentally, governments recognize that we have a problem called climate change. COP28 finally and formally recognized the root cause of this – fossil fuels. In this respect, there is more hope than when I took office, but we have to speed up mitigation efforts,” he said.

WMO has launched a new Global Greenhouse Gas Watch initiative, paving the way to a large-scale multilateral collaboration to strengthen observations and inform greenhouse gas emissions reduction.

“The private sector has also become very active with climate solutions, and the price of solar and wind power has fallen and will continue to do so,” says Prof. Taalas.

Renewables now dominate new sources of supply. In 2022 alone, 83% of new capacity was renewable, with solar and wind accounting for most additions. Today, some 30% of power generation globally is renewable, due to rapid deployment in the past decade, according to a report from WMO and the International Renewable Energy Agency released at COP28.

Three people sitting at a table and giving the thumbs up.
Dr Wenjian Zhang - Prof. Petteri Taalas - Dr Elena Manaenkova


Prof. Taalas raised the profile of WMO on the global agenda, by promoting science for decision-making. Prof Taalas has acted for many years as a core climate adviser to the UN Secretary General António Guterres, who has made climate change his top priority. Mr Guterres announced the Early Warnings for All Initiative on the occasion of World Meteorological Day 2022 and it is now one of the top priorities of the organization.

He also reformed the structure of WMO to ensure it meets modern day challenges, and forged new partnerships with the private sector.

Dr Elena Manaenkova joined WMO in 2003 and served as Deputy Secretary-General since 2016. Dr Wenjian Zhang served as Assistant Secretary-General since 2016. They are finishing their official mandate on 31 December at the same time as Prof. Taalas, leaving a legacy of commitment to science and society.

The World Meteorological Organization (WMO) is a specialized agency of the United Nations responsible for promoting international cooperation in atmospheric science and meteorology.

WMO monitors weather, climate, and water resources and provides support to its Members in forecasting and disaster mitigation. The organization is committed to advancing scientific knowledge and improving public safety and well-being through its work.

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  • Clare Nullis WMO media officer cnullis@wmo.int +41 79 709 13 97
  • WMO Strategic Communication Office Media Contact media@wmo.int