Understanding How the Air Quality Index Works
Air quality levels have received a lot of attention in recent months.
In the wake of COVID-19 lockdowns, many places reported a marked increase in air quality. Northern India captured the world’s attention when it was reported that the Himalayan mountain range was visible for the first time in decades.
On the flipside, later in the summer, wildfires swept over the Pacific Northwest and California, blanketing entire regions with a thick shroud of smoke that spanned hundreds of miles.
How is air quality measured, and what goes into the health scores we see?
Measuring the Air Quality Index
When we see that air quality is “good” or “unhealthy”, those public health categories are derived from the Air Quality Index (AQI).
In the U.S., the AQI is calculated using five major air pollutants regulated by the Clean Air Act:
- Ground-level ozone
- Carbon monoxide
- Sulfur dioxide
- Particle pollution, also known as particulate matter
- Nitrogen dioxide
Some countries have a slightly different way of calculating their scores. For example, India also measures levels of ammonia and lead in the air.
To make these readings more accessible, the AQI has a scoring system that runs from 0 to 500, using data collected from air monitoring stations in cities around the world. Scores below 50 are considered good, with very little impact to human health. The higher the score gets, the worse the air quality is.
To make communicating potential health risks to the public even easier, ranges of scores have been organized into descriptive categories.
|AQI Score Range||AQI Category||PM2.5 (μg/m³)||Health Risks|
|0-50||Good||0-12.0||Air quality is satisfactory and poses little or no risk.|
|51-100||Moderate||12.1-35.4||Sensitive individuals should avoid outdoor activity.|
|101-150||Unhealthy||35.5-55.4||General public and sensitive individuals in particular are
at risk to experience irritation and respiratory problems.
|151-200||Unhealthy||55.5-150.4||Increased likelihood of adverse effects and aggravation
to the heart and lungs among general public.
|201-300||Very Unhealthy||150.5-250.4||General public will be noticeably affected.
Sensitive groups should restrict outdoor activities.
|301+||Hazardous||250.5+||General public is at high risk to experience strong
irritations and adverse health effects. Everyone
should avoid outdoor activities.
While all the forms of atmospheric pollution are a cause for concern, it’s the smaller 2.5μm particles that get the most attention. For one, we can see visible evidence in the form of haze and smoke when PM2.5 levels increase. As well, these fine particles have a much easier time entering our bodies via breathing.
There are a number of factors that can increase the concentration of a region’s particulate matter. Some common examples include:
- Coal-fired power stations
- Cooking stoves (Many people around the world burn organic material for cooking and heating)
- Smoke from wildfires and slash-and-burn land clearing
Wildfires and Air Quality
Air quality scores can fluctuate a lot from season to season. For example, regions that are reliant on coal for power generation tend to see AQI score spikes during peak periods.
One of the biggest fluctuations occurs during wildfire season, when places that typically have scores in the “good” category can see scores reach unsafe levels. In 2020, Eastern Australia and the West Coast of the U.S. both saw massive drops in air quality during their respective wildfire seasons.
Luckily, while these types of fluctuations are extreme, they are also temporary.
Correction: Graphics and article updated to include nitrogen dioxide.
UN Sustainable Development Goals: How Companies Stack Up
Are companies making progress in meeting the UN Sustainable Development Goals? This tracker shows how companies are measuring up.
The UN SDGs: How Companies Stack Up
Environmental, social, and governance (ESG) investing witnessed a breakthrough year in 2020 with the most fund inflows on record.
Importantly, for companies that are judged according to ESG metrics, one way to track their progress is through their alignment to the UN Sustainable Development Goals (SDGs).
Established in 2012, the UN SDGs are a blueprint for creating a more sustainable future by 2030 that have been adopted by 193 countries worldwide.
As investors and stakeholders pay closer attention to sustainability concerns, this graphic from MSCI breaks down how companies stack up according to their alignment to the UN SDGs.
How Were Companies Measured?
To track companies net contribution to the UN SDGs, companies were scored by their positive or negative contribution to each of the 17 goals.
The 17 UN SDGs are designed to achieve three primary objectives by 2030:
- Protect the planet
- End poverty
- Create prosperity and peace for all
Specifically, the framework centers on a discussion paper that was developed in partnership with the OECD in 2018. Company policies, operations, products and services, and practices are analyzed according to reported and publicly available information.
Tracking the Alignment of Companies
Across a universe of 8,550 companies in the MSCI All Country World Index, constituents were measured from strongly aligned to strongly misaligned to the UN SDGs.
|3||Good Health and Well-being||0||315||141||29|
|6||Clean Water and Sanitation||17||325||36||10|
|7||Affordable and Clean Energy||43||639||109||587|
|8||Decent Work and Economic Growth||25||1269||52||17|
|9||Industry, Innovation, and Infrastructure||68||844||137||9|
|11||Sustainable Cities and Communities||0||0||167||19|
|12||Responsible Consumption and Production||115||855||150||598|
|14||Life Below Water||0||36||151||92|
|15||Life on Land||0||0||128||17|
|16||Peace and Justice Strong Institutions||0||135||241||27|
|17||Partnerships to Achieve the Goal||0||401||152||22|
Source: MSCI ESG Research LLC as of August 11, 2020
Broadly speaking, companies fell mostly in the middle—roughly 38% were aligned while almost 55% were misaligned or neutral. Meanwhile, just 0.2% of companies were strongly aligned to the UN SDGs.
Overall, one of the most strongly aligned goals was Responsible Production and Consumption, with 115 companies meeting this criteria. Specifically, these include companies that are building sustainable infrastructure, energy efficiency, or creating green jobs.
Interestingly, the worst performing goal was also Responsible Production and Consumption, with over five times as many companies (598) strongly misaligned. Along with this goal, both Climate Action and Affordable and Clean Energy each had over 500 companies strongly misaligned.
UN SDGs: A Sector Focus
Unsurprisingly, SDG-alignment varied widely according to company sectors.
Educational companies, for instance, represented the highest level of alignment to Gender Equality. Meanwhile, 18% of 425 utilities companies assessed ended up aligning with Clean and Affordable Energy goals.
As one would expect, the energy sector lagged behind. In 2020, fossil fuels were a key source of revenue for 91% of the companies in the energy business. In fact, just three companies derived over 50% of their revenues from green alternatives: REX American Resources, Renewable Energy Group, and Verbio.
A Call to Action?
Despite the growing wave of interest in ESG investing, the reality is that progress to meet the UN SDGs has been slower going than expected.
However, a greater number of individuals, stakeholders, and activists are sounding the alarm. Today, over 3,000 signatories representing trillions in assets under management have committed to the UN Principles of Responsible Investment, which has established six key actions for ESG investing. Now, many companies are required to report their ESG disclosures in Europe.
Along with these key markers of progress, investors can move the dial by tracking a company’s alignment to sustainable development goals.
Mapped: The Greenest Countries in the World
The world’s growing focus on sustainability is a clear sign of the times. This map ranks the 40 greenest countries in the world.
Mapped: The Greenest Countries in the World
From widening wealth disparity to the environmental ramifications of economic development—the growing focus on global sustainability is a clear sign of the times.
Research reveals that when a sustainable ethos is applied to policy and business, it typically bodes well for economies and people alike. By providing benchmarks for those decisions, indexes like Yale’s Environmental Performance Index (EPI) can be critical to measuring national sustainability efforts.
The above map interprets the EPI ranking of 180 economies across 32 environmental health indicators by narrowing in on the top 40 greenest countries.
Who’s the Greenest of them All?
Despite the decades-long trend of globalization, national environmental policies have proved to be widely divergent. The EPI report confirms that those policies—and their positive results—are highly correlated with national wealth.
This is evidenced in the global EPI distributions, seen below:
|OVERALL RANK||COUNTRY||SCORE||REGIONAL RANK|
|24||United States of America||69.3||21|
|42||United Arab Emirates||55.6||2|
|63||Antigua and Barbuda||48.5||10|
|65||St. Vincent and Grenadines||48.4||11|
|69||Trinidad and Tobago||47.5||14|
|78||Bosnia and Herzegovina||45.4||18|
|119||São Tomé and Príncipe||37.6||10|
|124||Central African Republic||36.9||12|
|125||Dem. Rep. Congo||36.4||13|
|146||Papua New Guinea||32.4||20|
|154||Republic of Congo||30.8||26|
Regional grouping in the report include: Global West, Asia-Pacific, Eastern Europe, Former Soviet States, Greater Middle East, Latin America & Caribbean, Southern Asia, and Sub-Saharan Africa
Scandinavian countries, which tend to have a high GDP per capita, show strong and consistent results across EPI parameters. Denmark for instance—which ranks first overall—leads the world in slowing its growth in CO2 emissions. Meanwhile, neighbor Sweden leads in landfill and recycling treatment, while wastewater treatment is led by a handful of countries within and beyond Scandinavia including Denmark, Finland, the Netherlands, Singapore, and Sweden.
In North America, Canada claims top spot in the biodiversity and habitat category, while the U.S. ranks sixth in agricultural diversity globally. In Asia, Singapore leads the world in fishery health and sustainability.
Ultimately, it appears the world’s greenest countries tend to focus on all areas of sustainability, while laggard countries show more uneven performance across categories.
What Does “Green” Mean?
Each high-level performance indicator with the EPI, like “environmental health”, is broken into subsections. Nations are scored on each subsector on a scale up to 100. As a result, multiple countries can rank first in any given category.
By evaluating national sustainability on a scale that is unrelated to other nations, we get a clearer idea of comparative national progress, beyond a basic ranking.
For instance, 30 countries tie for first in marine protection, all with scores of 100. This shows that many economies are prioritizing this area of sustainability.
The EPI categories and subsectors are shown in the diagram below:
Each section is weighted differently, and is reflected as a percentage within the index. For example, Ecosystem Vitality accounts for 60% of the EPI, Climate Change makes up 24% of a country’s score, and CO2 emission reduction is weighted at 13.2%.
The Cost of Being Green
Infrastructure costs are one reason why wealthier nations tend to fare better across sustainability measures. Everything from air pollution reduction and water treatment, to hazardous waste control and mitigation of public health crises are especially expensive—but have a huge potential impact on citizens.
This trend can be seen the scatterplot, which demonstrates the distribution of economies evaluated by the EPI:
For a more detailed look, the table below highlights the GDP per capita of each of the top 40 greenest countries, based on data from the World Bank and Statista:
|COUNTRY||EPI SCORE||GDP Per Capita||RANK|
|United States of America||69.3||65,298||24|
Despite the strong correlation between GDP per capita and EPI score, developing countries do not have to abandon sustainability efforts. China for instance leads the world in the adoption of electric vehicle technology.
Although some rankings can seem prosaic, indexes like the EPI provide a helpful benchmark for economies to compare efforts. It also allows governments to iterate and build upon environmental strategies and investments by highlighting what is and isn’t working.
CO2 emissions, for instance, are a major driver of climate change. Although the global economic stall has led to a temporary dip of CO2 emissions in early 2020 (a slower growth rate than the 11% expected rise), global emissions still continue.
However, the EPI shows that investments have impact. High-level sustainability efforts—political commitment, media coverage, regulations—can deliver results, even at the grassroots level.
Money1 month ago
The Richest People in the World in 2021
Green1 month ago
Mapped: The Greenest Countries in the World
Misc2 months ago
The World’s Most Searched Consumer Brands
Markets1 month ago
World Beer Index 2021: What’s the Beer Price in Your Country?
Markets2 months ago
The Population of China in Perspective
Sponsored2 months ago
The Carbon Footprint of Trucking: Driving Toward A Cleaner Future
Money1 month ago
Ranked: The World’s Black Billionaires in 2021
Markets2 months ago
The Buffett Indicator at All-Time Highs: Is This Cause for Concern?