UN Geneva - Multimedia Newsroom : WMO Press conference: Global Air Pollution

OK, Thank you very much for attending, joining us at this press conference.

It's the World Meteorological Organisation press conference on the annual Air Quality and Climate Bulletin.

Thank you as ever to UN Television for for hosting us for making this possible.

Just a couple of housekeeping issues while the cameras are setting up.

So we sent out the press release under embargo this morning.

If you want access to the full report, click the top link of the press release and that will take you onto the embargoed page, which takes you to the to the report.

The press releases are being or have been translated into all languages.

So if you, if you need a language, please, please, please let me know and I'll forward it to you just for, to help you with your, with your writing, to give you a little bit of time for your writing.

We've set the embargo for tomorrow.

So because it is a technical subject, just so you don't feel under pressure to, to, to write about it quickly.

So we've set it for the embargo for tomorrow at 6:00 AM Geneva time.

And the timing of this bulletin is comes ahead of the International Day of Clean Air for Blue Skies, which is every year on the 7th of September, which is which is Sunday.

If you need more information on that, the actual event is being coordinated by UNIP and the Climate and Clean Air, Climate and Clean Air Coalition, with whom we work closely.

So if you need me to facilitate any contacts with what they're doing, please just please just let me know.

So without any further ado, I'll introduce you to our expert speakers today.

On my far left I have Doctor Paulo Larsh, who is the chief of global, the Global Atmosphere Watch programme at the World Meteorological Organisation.

And in the centre is Doctor Lorenzo Labrador, who is a scientific officer at WMO and he's the coordinator of this bulletin.

The press conference will be in English, but we can take questions in French.

Both my colleagues speak French and if there's a need for any interviews afterwards in Spanish, we can also accommodate that.

So we'll start with a few introductory words from from, from Paulo.

[Other language spoken]

Thank you very much, Claire.

I just wanted to introduce this this bulletin, which is part of a bulletin series that we published every year at the WMO.

And you have in the slide there the four bulletins.

The first one is it's been released already in, in July and it's about airborne dust.

How is the dust affecting the, the climate?

How is dust transferred, transported to from a region to another?

This is the really the purpose of this dust bulletin.

Then we have today the Air Quality and Climate Bulletin and I will leave my colleague Lorenzo to discuss the the findings we have on the Tuesday, September 16th, the release of the Ozone Bulletin, which will discuss recovery of the ozone, the stratospheric ozone layer.

And then ahead of the of the UN gap report in October, we'll have the WMO greenhouse gas bulletin that will be launched.

This last bulletin was discussed the most recent information about the CO2 levels and other greenhouse gas levels in the atmosphere and their impacts.

So this is just a very short introduction on the the our series of publications on atmospheric composition, which you know that as is affecting climate, is affecting health and many other sectors of the society.

So I will leave now the the floor to my colleague Lorenzo.

Thank you very much, Paulo.

It is my pleasure to present the 2025 Air Quality and Climate Bulletin.

As we have done in previous years.

This is the 5th edition of the Bulletin and WMO produces it to coincide with the The Clean Air for Blue Skies Day.

So as we previous editions, the main message of the Bulletin is that air quality and climate change have to be tackled as interconnected issues.

They cannot be tackled separately because they share sources and because the components that affect air pollution affect climate change and vice versa.

So this is basically the the standing message that we have been trying to convey through our previous editions of the Bulletin, and this continues to be the case each year.

The Air Quality and Climate Bulletin seeks to report on the state of air quality and its interconnections with climate change, and it also tries to reflects on the trends and geographical distributions of air pollution across the world.

This is done via a series of contributions by the scientific community that advises the world meteorological organisations on matters related to air quality and climate change.

So we call upon them to give us examples of how these interdependence between our climate, air, air quality and climate change happens, and they provide contributions to us that reflect that.

They use, by the way, data in many cases from the network of stations that the WMO Global Atmosphere Watch programme holds around the world.

So we have reliable data that is coordinated in great part by the World Meteorological Organisation.

The 2025 edition of the Bulletin stresses 2 particular aspects.

Basically, they focus on the effects of aerosols and also the influence of man made activities on aerosols themselves.

It also sheds light on the very important infrastructure for monitoring the composition of the atmosphere that is necessary to collect the data that will result in these studies, and not only the studies, but also the measures that governments put in place to alleviate the effects and mitigate the effects of air quality and climate change around the world.

The bulletin usually starts by giving a a detailed view of the year, the previous year, in this case 2024 situation of particulate matter 2.5.

Those are basically those particulates in the air that have a diameter of 2.5 micrometres of or less that are very small and therefore also have the most consequences on human health because they can be inhaled by people and animals and basically stay and affect the the the respiratory tract.

So what we do is that we look at the series of modelling studies from different sources.

And in this year we have three studies, three sources.

Basically, we have three different models with three different inputs looking at PM anomalies or basically how much 2024 differed with respect to the 2003 to 2024 reference and see what may have been the causes.

We are very happy to report that despite the models being different, they all came to very similar conclusions regarding the pattern of PM distribution around the world.

And what we can see is that we have very marked PM 2.5 anomalies in the Amazon basin, northern Canada, Eastern Siberia and that the Indian subcontinent as well.

The in the case of the Amazon base in Canada and Siberia, this is most likely due to very strong wildfire season.

So those are mostly PM 2.5 that come from wildfires and basically have the power to degrade air quality far away from the places that their issue.

Can you get to the previous slide please?

[Other language spoken]

We can also see positive anomalies in the Indian subcontinent and that is due to a series of different factors including man made emissions which include traffic, construction and biomass burning and cooking fires as well.

And we also see a positive anomaly over the Atlantic Ocean, which is most likely due to transport of Saharan dust from Africa across the Atlantic, which is an event that we tend to see every year as well.

On the flip side, we see negative anomalies particularly over Eastern China, which is a reflection of the decrease in emissions, the cutting emissions that we have had there in the last years.

So that is good news.

We also have some negative anomalies over Eastern Africa, which is A to an extent a reflection of a relatively mild dust storm season over that continent.

So while the three models agree on the general pattern of PM distribution around the world, there are differences concerning how much PM there was in each.

But we're happy to report that the despite the fact that three models being different and using different meteorology, the reports that the patterns are pretty much the same, which leads us to say that the scientific community has a fairly solid understanding of the processes that lead 2:00 PM anomalies around the world.

So we see basically that the wildfires are a recurrent pattern and we have had that in previous PM anomaly reports in previous politics whereby the the strongest signal regarding PM anomalies usually come from wildfires, be it in the Amazon basin or the northern, the northern, the northern part of the American continent or Siberia where we usually have strong wildfire seasons.

The bulletin, as I said before, shed slides on the role of aerosols and the influence that man man made activities have on aerosols as well.

And, and we picked an example to try to disentangle the very complex interaction between aerosols, health and climate change.

And what we used as an example was the reduction reduction in sulphur emissions mandated by the Marple 6 measures put in place by the International Admire Time organisation regarding shipping fuels.

Basically, they realised that the contents of sulphur in shipping fuels was leading to increases in the cases of premature mortality and asthma.

So they mandated that sulphur content in shipping fuel should be reduced and that that that was the Marple 6 measures put in place in 2020.

And we have seen as a result a decrease in more in premature mortality and a decrease in childhood asthma cases, particularly in the South Asia and Africa as a result of these of these measures.

This is the good part of the story.

So we have a marked reduction in improvement in air quality as a result of a reduction in pollutants in certain fuel.

But on the flip side, we also see that the reduction in the sulphates aerosols, which is a consequence of the reduction in sulphur emissions from these fuels, also unmask the real warming of greenhouse gases.

And what we have had is a very slight in or slight increase in the net radiative forcing, the global annual net radiative forcing as a result of the decrease in the sulphur sulphate contents in the atmosphere.

So that results or translates into a very slight increase in the temperature of 0.04° in 2025.

So what we have here, and this is very important to emphasise, is not an increase in temperature due to aerosols, but rather an unmasking of the true warming of greenhouse gases as a result of the offset that these aerosols were having.

Because sulphide aerosols basically made clouds brighter and they reflect more light into space which basically cools off temperatures a bit.

So this is but one example of these very complex interplace between aerosols and greenhouse gases and between air quality and climate change as a whole.

And there are many other examples, but in order to try to drive the message we decided to use this particular example.

Next we have another article with also also shed slides on aerosol, but this time it is on the persistence of 4 episodes in the indoor Gangetic plane.

The Indo Gangetic plain is this area in the Indian subcontinent that's essentially spans eastern Pakistan, the whole of northern India, the whole of Bangladesh and and that is very active in agricultural activities.

[Other language spoken]

So it's a very densely populated area.

You'd usually have fog episodes at the end of the monsoon season when the when the monsoon ends and you have an inversion in the temperature that traps air and suppresses the ability of the atmosphere to mix itself, so you have fog.

However, what has been noticed is that in later years the fog episodes have become more consistent and longer.

And what the study that we highlight has shown is the fact that man made activities and particularly the aerosols that come from man made activities, including construction, the burning of crop residue at the end of the monsoon season and the burning of domestic fuels have resulted in an increase in what you call fog condensation nuclei or the very tiny particles that the fog droplets coalesce around to form the fog.

So we have seen that there is an increase in the fog length and fog intensity episodes at the end of the monsoon season and the studies point to aerosols issuing from man made sources as one of the leading causes of these persistent fog episodes.

It is also worth noting that there are chemical reactions that happen in the fog droplets together with the water in the fog and the aerosols that made these fog droplets more harmful to human health as well.

So we have two aspects here and this is part of the PM anomalies that we can see in the in the slide that we showed at the beginning regarding the PM 2.4 anomalies.

So this is all as we can see interconnected.

So what this point is that that governments needs to put in place measure to address these these air quality concerns that have an impact on human health.

Then we have the third article that shows light on ozone on aerosols, excuse me is next slide please is one that correlates the very intense wildfire season in 2024 over the Amazon basin with a measurable degradation in air quality on a host of different cities in South in South America.

What we saw was that PM levels increase significantly to coincide with the PM increases that we saw as a result of the wildfires, particularly in the month of August of 2024.

You can see that very strong signal in the top plot in the central part of South America, basically the Amazon basin, where there was a very, very strong biomass burning season, wildfire season.

And as a result, a lot of PM 2.5 was issued.

That was picked up as far as cities in in in Chile, particularly Santiago and Vina Del Mar, also as Far East as the state of Santiago, in the state of the state of Sao Paulo in Brazil, excuse me, and also in Ecuador.

So what do you see in the two plots below the map is the sharp increases in PM 2.5 levels that coincided pretty much with the peak activity in fires in the Amazon basin back in 2024.

So what this tells us as is that even though you are quite far from the sources of fires, these, the smoke pollution and the PM 2.5 that comes from those fibres have the power to basically go across borders and travel very long distances and degrade air quality in faraway cities.

We have also seen that basically from wildfires as far I feel as Canada making it all the way across Europe.

We had that last year and we had that this year as well.

So you have a degradation in air quality across continents when the meteorological conditions are right to transport the smoke and the pollution across the oceans.

So what we have from this fire is essentially A witches brew of components that pollute the air including PM 2.5 and a host of other administrate components at the great air quality.

But the main one that we can point out to here is is PM 2.5.

Then we have another article when we have a look at the breakthroughs that have been done in modelling Poland.

Since we basically have about 20% of the global population susceptible to pollen allergies, it is very important that we make breakthroughs in better predicting the start and end and the severity of of the pollen season around the world every year.

In last year bulletins we reported on the breakthroughs that have been made to in the instant data collection for pollen, particularly in Europe where they are now automated pollen monitoring stations that basically collecting real time pollen data that can be used now in models to make better predictions of what the pollen intensity is in places around the world.

So what this will enable is that when those two elements are put together real near real time data, pollen and good models you can.

Be assured that there will be better forecasts of pollen around the world and that will result in better personalised care for those people suffering from pollen allergies as well.

We also reported that this this collection of data that we use in order to report on PMS and to report on air quality degradation around the world will not be possible if it were not for a global fit for purpose infrastructure for monitoring atmospheric composition around the world.

And we have basically all these studies that I showing you are the results of our ability to collect good and timely data and to quality control those data around the world in a very short time to produce these studies that can result in measures that governments can implement in order to make quality better air quality better around the world.

So we highlighted 2 examples where these monitoring infrastructure is important.

And one of them was basically the validation of satellite products used to monitor aerosols from space.

Satellites can also look down on the atmosphere and tell us what the states of aerosols are.

But in order for those products that come from satellites to be validated, they need to be compared to ground based observations of aerosols.

And we have a dedicated network of stations that are coordinated by the Global Atmosphere Watch programme that can be used to validate and calibrate those those products.

So the Earth Care mission is but one example that where a satellite product was a satellite mission, use ground based data to validate those products.

We have a second example, which is a very nice network of stations in the African continent that is used to measure deposition fluxes of atmospheric pollutants or basically the way atmospheric pollutants settle on to the ground and can contaminate and pollute basically water bodies and plants.

So and what we see is that while in certain areas we have a very solid and well established and monitoring network infrastructure, there are certain parts of the world, particularly developing countries that are sorely lacking that capability and have to rely mostly on modelling studies to assess the state of air quality.

So we the message that we would like to drive is that is very, very important to develop the monitoring network infrastructure, particularly in places that are lacking in those models.

So this is basically a bird side view of this year, air quality and the climate bulletin and I'm ready to take any questions that you may have.

OK, Thank you very much, Lorenzo.

So in a word, it's complicated, but we're trying to do our best to, to, to explain it.

So I will open the floor to questions.

Obviously this bulletin is on 2024, but I imagine, you know, if you do have questions on what's been happening this year, we will we, you know, we will be able to answer them.

And just to explain, Lorenzo talks a lot about negative anomalies.

In plain speak, that means lower than average.

[Other language spoken]

So anyway, so I'll give the floor to one in the room first of all, and then we'll go to the platform.

So if you could just introduce yourself.

Thank you very much.

[Other language spoken]

How this how this bulletin can be used?

[Other language spoken]

By city authorities or states to to actually tackle air quality.

[Other language spoken]

That's a very good question, Robin.

And the the intended audience of the bulletin is precisely the the people in the street and also authorities at both the national and regional level.

We would hope that the examples that we highlight in the bulletin each year can be a snapshot of basically the situation around the world of the most pressing issues regarding air quality.

And that this information can be used wherever it is possible and that whatever it addresses a particular region to basically implement better measures for tackling air quality.

Basically what people can do is realise that for example, a fit for purpose atmosphere monitor network can can be one of the best responses to basically monitor where the air quality is over a given country or region.

And that that will enable policy makers to a price or basically evaluate what the situation is regarding air quality and put measures in place.

It'll be hard to use the specific examples because they may not cover areas of interest for particular people in particular cities, but they give a pretty good snapshot of what the general situation is regarding, say, particular matter around the world.

But the main message here would be OK, as as long as we have observations and reliable observations around the world, we'll be in a better position to assess what the state of air quality is and therefore what measures to take to tackle the negative effects of of air quality.

Thank you very much.

We'll go to the platform now, so FA Spanish news agency Antonio Porto.

[Other language spoken]

Ask about the wildfires that have ravaged Spain this summer.

Especially I would like.

To know how they may affect the air quality of Spain of the whole.

Region.

Or the whole planet in the short term, medium term, long term?

[Other language spoken]

Many thanks for your question, Antonio.

The the the current wildfire season in the Iberian Peninsula has been one for the records.

For instance, the Copernicus Atmospheric Monitoring Services has highlighted that this has been, in terms of community emissions of CO2, the strongest season that has happened since they started taking records back in 2003, so the strongest season in 20 years.

So by estimates about 1% of the entire entire Iberian Peninsula has been affected by wildfires, which is basically a a very big area.

And the problem is that as I said before, air quality respects no boundaries.

So and the, the smoke and the pollution that issues from the wildfires in this record-breaking season in the Iberian Peninsula has been detected over Western Europe already.

So the the effects are not only limited to the Iberian Peninsula, but can travel basically throughout the rest of the the the European continent.

Likewise, what we have seen is that fires that come from as far afield as Canada have made it basic that not the fires, the pollution have made it across the Atlantic into into the European continent.

So we're seeing basically year on year and we have been reporting on that in previous editions of the air quality bulletin that wildfires are a perennial source of atmospheric pollutants to the atmosphere, particularly PM 2.5.

And yes, the the the very strong emissions from the fires in the Iberian Peninsula do have the potential to the greater quality not only over cities in Spain and Portugal, but also over the rest of the Western European continent and the rest of Europe as well.

[Other language spoken]

Staying on the platform, Olivia from Reuters, thank you very much for this briefing.

I would just like to know how much worse or better the picture was in 2024, just to put it in some context in comparison with previous years in terms of air quality.

And also secondly, I'm just curious to know from your perspective how concerned you are that maybe in 2025 we might start to?

[Other language spoken]

Things getting worse, or at least not getting much better.

I'm just thinking of, for example, President Donald Trump's administration's recent robot backs on climate policies that the second biggest carbon emitter.

And you were talking there about the need for globally kind of integrated policies to to target carbon emissions, which contribute to both air pollution and climate change.

Thanks for your two-part question Olivia.

I'll try to answer the first one.

The the first part first it it is very hard to say in general terms how the 2024 year compare in air quality compared to previous years.

What we can show is a snapshot and that's why we start with the PM anomalies section of the bulletin each year.

What we can see is that the patterns are very similar year on year.

For example, you have very strong PM sources as a result of wildfires both in the Amazon basin in Canada and Siberia.

We have seen that in previous years as well.

We know that the wildfire season has the tendency to be stronger and longer every year as a result of climate change.

So that is an issue and that is part of the reason why we see those patterns regarding wildfires and degradation of air quality in in wildfires.

So we can see that we're seeing a pattern in with respect to degradation of her quality in so far as it concerned PM 2.5 And we also see that there is a reduction in emissions in certain parts of the world, particularly Eastern China and Europe year on year.

So we see similar pattern there.

As to the magnitude, I'll be hard pressed to commend because that's that's that's a bit harder to do.

Concerning your, the second part of the question, we still have to see what the year 2025 will bring with respect to air quality and climate change.

What we can see is that, for example, the beginning of the year, we saw a very, very strong wildfire season in the US in January no less.

You remember the the very strong wildfires that affected the city of Los Angeles.

So we will have to see once those data have been analysed, what kind of effects that we'll have in the overall and global picture of air quality going forward.

With respect to the possible measures or or lack thereof in reduction of emissions in the US, We will have to see the effects of that going forward.

It's it's still very early to say.

Usually in order to see the effects of that, it takes a few years until you start to see patterns regarding that, but this is something that that will be keeping that the scientific community will be keeping an eye on.

[Other language spoken]

When we see that countries or regions or cities are taking measures to fight against bad air quality, it works and we see that in many areas an improvement of the air quality.

Obviously we need years to see this improvement.

It's not on comparing one year to the next that we can see how things are improving because metrology, because there are many factors that are that can be affecting from one year to the next.

But globally, in regions where these measures have been taken, there is a great improvement of the air quality.

This is this is important to say thank you very much.

I can't see any more questions on the platform and nothing in the room.

So if there's no more questions, I'll thank you very much indeed for your time.

Thank you again to UN Television for hosting us.

As I said, this is Andrew Embargo till tomorrow morning.

There are many other assets from our colleagues at UNET, UNET if you are interested, but that's all from as the World Meteorological Organisation.

And so the next bulletin we will be issuing is on ozone, the ozone bulletin, and that will be for the 16th of September, which is the International Day for the Preservation of the of the Ozone Layer.

So stay tuned and thank you very much.

WMO Press conference: Global Air Pollution - 04 September 2025