Environment

Visualized: Air Quality and Pollution in 50 Capital Cities

Published

11 months ago

October 7, 2023

Planet Anomaly

Featured Creator

Article/Editing:

Pallavi Rao

A chart comparing air quality in 50 capital cities around the world by average PM2.5 concentrations in 2022.

Comparing Air Quality and Pollution in 50 Capital Cities

We know bad air quality when we breathe it in—but how does it measure and compare across different cities?

To assess air quality, agencies measure the amount of particulate matter in an area to arrive at a number the resident population is breathing in over a period of time.

ℹ️ Airborne particulate matter (PM) is a complex mix of solids and aerosols and is defined by diameter for regulatory purposes. Particles with a diameter of 10 microns or less (PM10) are inhalable and can induce adverse health effects.

In this case, Planet Anomaly visualized the concentration of PM2.5 (fine particulate matter) in 50 select capital cities across the globe, using data from IQAir’s 2022 World Air Quality Report.

The report applied population-based adjustments to standardize its results and calculated an annual average of the data. If a city exceeded the WHO safety guideline of 5 micrograms per cubic meter (μg/m³) for annual average PM2.5 levels, it implied potential health risks for its residents.

Ranked: Capital Cities With the Best and Worst Air Quality

At the top of the list with the best air quality, Canberra, the capital of Australia, had an average PM2.5 level of 2.8 μg/m³ in 2022. Vehicle emissions and dust storms are the few sources of air pollutants in the city.

However, while Canberra did well in 2022, it had some of the worst air quality in 2020 when bushfire smoke blackened the skies.

Here’s the full list of all 116 capital cities measured by IQAir’s report, ranked by air quality from best to worst.

Rank	City	Country	Region	2022 Average PM2.5 Concentration
1	Canberra	🇦🇺 Australia	Oceania	2.8
2	Hamilton	🇧🇲 Bermuda	North America	3.0
3	Reykjavik	🇮🇸 Iceland	Europe	3.3
4	San Juan	🇵🇷 Puerto Rico	North America	3.3
5	Noumea	🇳🇨 New Caledonia	Oceania	3.5
6	Saint George’s	🇬🇩 Grenada	Central America	3.8
7	Tallinn	🇪🇪 Estonia	Europe	4.8
8	Port of Spain	🇹🇹 Trinidad & Tobago	Central America	5.0
9	Helsinki	🇫🇮 Finland	Europe	5.5
10	Cape Town	🇿🇦 South Africa	Africa	6.7
11	Ottawa	🇨🇦 Canada	North America	6.8
12	Stockholm	🇸🇪 Sweden	Europe	6.8
13	Oslo	🇳🇴 Norway	Europe	6.9
14	Paramaribo	🇸🇷 Suriname	South America	7.0
15	Dublin	🇮🇪 Ireland	Europe	7.1
16	La Paz	🇧🇴 Bolivia	South America	7.3
17	Lisbon	🇵🇹 Portugal	Europe	7.5
18	San Jose	🇨🇷 Costa Rica	Central America	7.9
19	Phnom Penh	🇰🇭 Cambodia	Asia	8.3
20	Vaduz	🇱🇮 Liechtenstein	Europe	8.3
21	Copenhagen	🇩🇰 Denmark	Europe	8.7
22	Luanda	🇦🇴 Angola	Africa	8.8
23	Managua	🇳🇮 Nicaragua	Central America	8.9
24	Panama	🇵🇦 Panama	Central America	9.0
25	Tokyo	🇯🇵 Japan	Asia	9.2
26	Madrid	🇪🇸 Spain	Europe	9.5
27	Kyiv	🇺🇦 Ukraine	Europe	9.5
28	London	🇬🇧 UK	Europe	9.6
29	Washington	🇺🇸 U.S.	North America	9.8
30	Taipei	🇹🇼 Taiwan	Asia	9.9
31	Amsterdam	🇳🇱 Netherlands	Europe	10.1
32	Tegucigalpa	🇭🇳 Honduras	Central America	10.2
33	Vienna	🇦🇹 Austria	Europe	10.5
34	Bern	🇨🇭 Switzerland	Europe	10.5
35	Brussels	🇧🇪 Belgium	Europe	10.6
36	Moscow	🇷🇺 Russia	Europe	10.8
37	Budapest	🇭🇺 Hungary	Europe	11.2
38	Montevideo	🇺🇾 Uruguay	South America	11.3
39	Nairobi	🇰🇪 Kenya	Africa	11.5
40	Podgorica	🇲🇪 Montenegro	Europe	11.8
41	Prague	🇨🇿 Czech Republic	Europe	11.9
42	Berlin	🇩🇪 Germany	Europe	12.6
43	Rome	🇮🇹 Italy	Europe	12.6
44	Paris	🇫🇷 France	Europe	12.7
45	Georgetown	🇬🇾 Guyana	South America	12.7
46	Singapore	🇸🇬 Singapore	Asia	13.3
47	San Salvador	🇸🇻 El Salvador	Central America	13.4
48	Bratislava	🇸🇰 Slovakia	Europe	13.4
49	Pristina	🇽🇰 Kosovo	Europe	13.7
50	Ankara	🇹🇷 Türkiye	Asia	14.0
51	Buenos Aires	🇦🇷 Argentina	South America	14.2
52	Hong Kong	🇭🇰 Hong Kong SAR	Asia	14.4
53	Tirana	🇦🇱 Albania	Europe	14.5
54	Vilnius	🇱🇹 Lithuania	Europe	14.5
55	Metro Manila	🇵🇭 Philippines	Asia	14.6
56	Bogota	🇨🇴 Colombia	South America	15.1
57	Warsaw	🇵🇱 Poland	Europe	15.3
58	Kinshasa	🇨🇩 DRC	Africa	15.5
59	Ljubljana	🇸🇮 Slovenia	Europe	16.2
60	Tbilisi	🇬🇪 Georgia	Europe	16.3
61	Nicosia	🇨🇾 Cyprus	Europe	16.4
62	Bucharest	🇷🇴 Romania	Europe	17.1
63	Kuala Lumpur	🇲🇾 Malaysia	Asia	17.6
64	Algiers	🇩🇿 Algeria	Africa	17.8
65	Bangkok	🇹🇭 Thailand	Asia	18.0
66	Seoul	🇰🇷 South Korea	Asia	18.3
67	Guatemala City	🇬🇹 Guatemala	Central America	18.5
68	Baku	🇦🇿 Azerbaijan	Asia	18.9
69	Sofia	🇧🇬 Bulgaria	Europe	19.1
70	Athens	🇬🇷 Greece	Europe	19.2
71	Tel Aviv-Yafo	🇮🇱 Israel	Middle East	19.5
72	Dakar	🇸🇳 Senegal	Africa	20.4
73	Colombo	🇱🇰 Sri Lanka	Asia	20.9
74	Astana	🇰🇿 Kazakhstan	Asia	21.4
75	Ashgabat	🇹🇲 Turkmenistan	Asia	21.6
76	Mexico City	🇲🇽 Mexico	North America	22.1
77	Belgrade	🇷🇸 Serbia	Europe	22.1
78	Zagreb	🇭🇷 Croatia	Europe	22.4
79	Abidjan	🇨🇮 Ivory Coast	Africa	22.5
80	Chisinau	🇲🇩 Moldova	Europe	22.6
81	Antananarivo	🇲🇬 Madagascar	Africa	23.7
82	Yangon	🇲🇲 Myanmar	Asia	24.3
83	Lusaka	🇿🇲 Zambia	Africa	24.6
84	Lima	🇵🇪 Peru	South America	25.6
85	Santiago	🇨🇱 Chile	South America	25.8
86	Skopje	🇲🇰 North Macedonia	Europe	26.6
87	Vientiane	🇱🇦 Laos	Asia	27.6
88	Bishkek	🇰🇬 Kyrgyzstan	Asia	29.0
89	Beijing	🇨🇳 China	Asia	29.8
90	Accra	🇬🇭 Ghana	Africa	30.1
91	Ulaanbaatar	🇲🇳 Mongolia	Asia	30.6
92	Addis Ababa	🇪🇹 Ethiopia	Africa	31.3
93	Yerevan	🇦🇲 Armenia	Asia	31.4
94	Sarajevo	🇧🇦 Bosnia Herzegovina	Europe	32.4
95	Tashkent	🇺🇿 Uzbekistan	Asia	33.5
96	Tehran	🇮🇷 Iran	Asia	36.1
97	Jakarta	🇮🇩 Indonesia	Asia	36.2
98	Kampala	🇺🇬 Uganda	Africa	39.6
99	Hanoi	🇻🇳 Vietnam	Asia	40.1
100	Islamabad	🇵🇰 Pakistan	Asia	40.6
101	Kathmandu	🇳🇵 Nepal	Asia	40.7
102	Doha	🇶🇦 Qatar	Middle East	41.8
103	Kigali	🇷🇼 Rwanda	Africa	44.0
104	Khartoum	🇸🇩 Sudan	Africa	44.6
105	Riyadh	🇸🇦 Saudi Arabia	Middle East	46.2
106	Abuja	🇳🇬 Nigeria	Africa	46.5
107	Cairo	🇪🇬 Egypt	Africa	47.4
108	Dushanbe	🇹🇯 Tajikistan	Asia	47.7
109	Abu Dhabi	🇦🇪 UAE	Middle East	48.0
110	Kuwait City	🇰🇼 Kuwait	Middle East	57.5
111	Ougadougou	🇧🇫 Burkina Faso	Africa	63.0
112	Dhaka	🇧🇩 Bangladesh	Asia	65.8
113	Manama	🇧🇭 Bahrain	Middle East	66.6
114	Baghdad	🇮🇶 Iraq	Asia	86.7
115	New Delhi	🇮🇳 India	Asia	89.1
116	N’Djamena	🇹🇩 Chad	Africa	89.7

Hamilton, Bermuda (3.8 μg/m³) and Reykjavik, Iceland (3.3 μg/m³) rank second and third respectively, followed by three more capitals on island nations. In fact, nine of the top 10 capitals are situated directly on a coastline and take advantage of ocean breezes that can act as air filters.

Ranked 8th, the Port of Spain (capital of Trinidad & Tobago) is the last city whose air quality is considered safe (5.0 μg/m³) by the WHO.

From a broader perspective, fewer than 10% of all countries have air quality that meets safety guidelines.

Meanwhile, at the bottom of the list with the worst air quality, Chad’s capital city N’Djamena, recorded a PM2.5 concentration of nearly 90 μg/m³ per day in 2022—almost 18x the recommended WHO safety guideline.

Air Quality Correlates With Countries’ Income Levels

Perhaps the most striking feature of the rankings is how air quality worsens with countries that are in the low and middle-income categories and improves in high income countries.

As an example, compare the distribution of the ranks of capital cities in Asia (generally lower and middle income countries) versus capitals in Europe (general high income countries).

Air Quality Ranks	Cities in Asia	Cities in Europe
Top 20	3.33%	20.51%
20–40	6.67%	28.21%
40–60	13.33%	28.21%
60–80	23.33%	17.95%
80–100	36.67%	5.13%
100–116	16.67%	0.00%

The majority of European capital cities are ranked 20–60 versus Asian capitals which are mostly ranked 60–100.

Lower and middle income countries have larger structural economic concerns and many of them are still in the process of transitioning away from polluting materials that affect air quality.

This article was published as a part of Visual Capitalist's Creator Program, which features data-driven visuals from some of our favorite Creators around the world.

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Environment

Ranked: Top Countries by Total Forest Loss Since 2001

The country with the most forest loss since 2001 lost as much forest cover as the next four countries combined.

Published

5 months ago

April 5, 2024

Pallavi Rao

A cropped bar chart ranking countries by the total decrease in their forest area between 2001–21, measured in square kilometers.

Ranked: Top Countries By Total Forest Loss Since 2001

This was originally posted on our Voronoi app. Download the app for free on iOS or Android and discover incredible data-driven charts from a variety of trusted sources.

Forests are critical natural resources, often caught in the crosshairs of economic development. Thanks to expanding human settlement, agriculture, and industry, the world lost nearly 1 million square kilometers (km²) of forest cover since 2001.

But where has most of this deforestation occurred?

We rank the countries by the total decrease in their forest area between 2001 and 2021, measured in square kilometers along with their percentage decrease for context. All of this data was sourced from the World Bank.

A caveat to this data: countries are ranked by total forest loss, so countries with the largest forests feature predominantly on this list.

Which Country Has Lost the Most Forests (2001-2021)?

Brazil has lost more than half a million square kilometers of forest in the last two decades. Agricultural expansion for beef and soy production alongside mining and infrastructure growth are the primary drivers behind this large scale deforestation.

This has also caused periodic fires in the Amazon rainforest, drawing repeated alarm from around the world. In fact, Brazil has lost as much forest cover as the next four countries combined.

The table below lists the countries included in this graphic, as well as several others further down the ranking.

Rank	Country	Region	2001–21 Change (in km²)	% of Forest Loss
1	🇧🇷 Brazil	South America	-517,464	-9%
2	🇨🇩 DRC	Africa	-181,721	-13%
3	🇦🇴 Angola	Africa	-111,012	-14%
4	🇸🇩 Sudan	Africa	-106,213	-37%
5	🇮🇩 Indonesia	Asia	-95,903	-9%
6	🇹🇿 Tanzania	Africa	-80,220	-15%
7	🇵🇾 Paraguay	South America	-68,266	-30%
8	🇲🇲 Myanmar	Asia	-62,712	-18%
9	🇦🇷 Argentina	South America	-45,979	-14%
10	🇲🇿 Mozambique	Africa	-44,688	-11%
11	🇧🇴 Bolivia	South America	-42,791	-8%
12	🇨🇴 Colombia	South America	-36,001	-6%
13	🇳🇬 Nigeria	Africa	-32,661	-13%
14	🇵🇪 Peru	South America	-30,155	-4%
15	🇰🇭 Cambodia	Asia	-28,491	-26%
16	🇻🇪 Venezuela	South America	-28,130	-6%
17	🇲🇽 Mexico	North America	-26,732	-4%
18	🇿🇲 Zambia	Africa	-23,924	-5%
19	🇧🇼 Botswana	Africa	-23,660	-14%
20	🇨🇮 Cote d'Ivoire	Africa	-22,577	-45%

What is quickly apparent is how most of the countries on this list are from Africa and South America. A study found a correlation where developing economies tend to have higher deforestation rates than advanced economies. Former colonies have also experienced more forest loss than those that were not colonized.

In Asia, Indonesia’s burgeoning palm oil industry is a key driver to deforestation, though efforts are now being made to reverse its impact. Meanwhile, Cambodia experienced rapid clear-cutting for its growing rubber plantations and timber industry.

Finally, Myanmar has long contended with illegal logging, but the country’s ongoing civil war is styming conversation efforts.