In 2025, the world’s cleanest countries are not just global leaders in environmental health—they are also innovators in climate policy, renewable energy, and sustainable development. These nations have earned top rankings through rigorous assessment by the Environmental Performance Index (EPI) and the Climate Change Performance Index (CCPI), which together provide the most authoritative and data-driven evaluations of national environmental performance.

The EPI, developed by Yale and Columbia Universities, uses 58 indicators across 11 categories—ranging from air and water quality to biodiversity and climate policy—to rank 180 countries on how well they meet sustainability targets. The CCPI, meanwhile, evaluates 63 countries and the EU, covering over 90% of global greenhouse gas emissions, and assesses performance in GHG emissions, renewable energy, energy use, and climate policy.

These indices are vital tools for policymakers, businesses, and communities, offering a granular view of each country’s strengths and weaknesses, helping to set targets, track trends, and identify best practices for a sustainable future. High-ranking countries benefit from advanced regulatory frameworks, greener infrastructure, and new market opportunities for sustainable technologies. Here’s a closer look at what sets each of the top 10 apart in 2025:

1. Estonia (EPI Score: 75.3)

Estonia leads the world in cleanliness and sustainability, thanks to its extensive forest cover, effective use of bioenergy, and a strong focus on natural resource management. The country has set ambitious climate goals, including a 70% reduction in greenhouse gas emissions by 2030 and carbon neutrality by 2050.

Estonia achieved an 11.3% emissions reduction in late 2024, outpacing the rest of the EU, even as its economy grew. The capital, Tallinn, has become a beacon of urban sustainability, winning the ITB Earth Award 2025 for its zero-waste Song and Dance Celebration, which drastically cut single-use plastics and promoted circular economy practices.

Estonia’s environmental policies have also led to Europe’s cleanest air and ongoing investments in wind, solar, and energy storage. However, the country faces challenges in fully phasing out fossil fuels and balancing biomass production with forest conservation.

2. Luxembourg (EPI Score: 75.0)

Luxembourg stands out as a small nation with outsized environmental achievements, earning an EPI score of 75.0 in 2024 and a 4.1-point rise over the past decade. The country leads the world in water management, boasting a near-perfect score of 90.6 in Water Resources and an astounding 99.8 in Sanitation & Drinking Water. Over 55% of Luxembourg’s land is protected, contributing to a top-tier biodiversity score of 84.8.

The nation’s capital has pioneered green investments, while advanced wastewater treatment and strict EU-aligned standards keep pollution low. While Luxembourg excels in ecosystem vitality and heavy metal pollution control, it continues to work on reducing per capita greenhouse gas emissions and curbing tree cover loss.

3. Germany (EPI Score: 74.6)

Germany ranks third globally with an EPI score of 74.6 in 2024, marking a 4.4-point improvement over ten years. The country treats 100% of its urban wastewater, achieving a high 89.1 in Water Resources, and protects a significant share of its land and seas, reflected in its 82.4 Biodiversity & Habitat score.

Germany’s robust environmental policies are complemented by massive investments in green infrastructure and renewable energy. The nation’s cities are recognized for clean air, efficient public transport, and progressive urban planning. Germany’s approach demonstrates that sustainability can go hand in hand with industrial progress, though ongoing industrial emissions remain a challenge.

4. Finland (EPI Score: 73.7)

Finland secures the fourth spot with a 2024 EPI score of 73.7, though this reflects a slight decrease from its 2014 score. The country is a global leader in public health, scoring a perfect 100.0 in both Sanitation & Drinking Water and Heavy Metals. Finland’s well-managed forests, protected natural areas, and clean air contribute to its strong ecosystem vitality.

The nation’s deep cultural connection to nature is evident in its policies, which seamlessly integrate sustainability into daily life. Finland’s challenge lies in maintaining its high standards amid growing urbanization and climate pressures.

5. United Kingdom (EPI Score: 72.7)

The United Kingdom earns an EPI score of 72.7 in 2024, up by 2.1 points over the past decade. The UK has made significant progress in reducing carbon emissions, largely through aggressive wind energy deployment and expanded recycling programs. Urban green spaces and biodiversity conservation have improved city livability and environmental health.

The UK continues to update its climate policies to meet international targets, but faces ongoing challenges with air quality in some metropolitan areas and the need for further emissions reductions.

6. Sweden (EPI Score: 70.5)

Sweden ranks sixth with a 2024 EPI score of 70.5, showing a modest 1.6-point increase over ten years. The country’s energy mix is dominated by hydropower and wind, and it is a pioneer in negative emissions technologies.

Sweden’s cities are models of sustainable urban development, and the nation’s commitment to clean air, water, and biodiversity is unwavering. However, Sweden faces pressure to further reduce emissions from transportation and industry to meet its ambitious climate goals.

7. Norway (EPI Score: 70.0)

Norway holds the seventh position with a 2024 EPI score of 70.0, up 3.6 points over the last decade. The country boasts nearly universal access to clean drinking water and sanitation, and its electricity is almost entirely supplied by hydropower.

Norway’s proactive climate policies and investments in electric mobility and carbon capture have resulted in some of the world’s lowest per capita emissions. The country’s challenge is balancing oil and gas exports with its climate commitments.

8. Austria (EPI Score: 69.0)

Austria scores 69.0 on the 2024 EPI, reflecting a slight decrease of 0.3 points over ten years. The country excels in maintaining clean cities and countryside through strict agricultural and chemical regulations. Austria’s public transport system and urban planning support eco-living, while strong environmental laws ensure high water quality and effective waste management.

Austria’s challenge is to address areas of stagnation and reinvigorate progress on climate adaptation and emissions reduction.

9. Switzerland (EPI Score: 68.0)

Switzerland earns a 2024 EPI score of 68.0, up 1.8 points over the last decade. The country is renowned for its pristine landscapes, robust waste management, and advanced water treatment systems.

Switzerland’s environmental protection laws and public engagement in sustainability initiatives help maintain high living standards and ecological health. However, Switzerland must continue to innovate in renewable energy and reduce its ecological footprint to stay ahead.

10. Denmark (EPI Score: 67.9)

Denmark rounds out the top ten with an EPI score of 67.9 in 2024, a 1.7-point increase over ten years. The nation is a global leader in wind energy and urban planning that prioritizes cycling and green spaces. Denmark’s comprehensive recycling policies and low pollution levels make it a model for clean living. 

The country’s ongoing challenge is to further cut emissions from agriculture and transportation while maintaining economic growth.

How Are These Rankings Determined?

Environmental Performance Index (EPI):

• Uses 58 indicators across 11 categories, including air quality, water and sanitation, biodiversity, habitat protection, and climate policy.
• Weights environmental health (40%) and ecosystem vitality (60%) to reflect both immediate human well-being and long-term sustainability.
• Draws data from the WHO, UN, and other global agencies, providing a scorecard for each country and highlighting leaders and laggards.

Climate Change Performance Index (CCPI):

• Assesses four main categories: GHG emissions (40%), renewable energy (20%), energy use (20%), and climate policy (20%).
• Uses 14 indicators, combining quantitative data (from IEA, FAO, UNFCCC) and qualitative expert assessments of national and international climate policy.
• Covers 63 countries and the EU, representing over 90% of global GHG emissions.

These indices are not just academic—they guide policy, inform investment, and help countries benchmark progress toward sustainability goals. High-ranking countries typically have strong regulatory frameworks, transparent governance, and engaged civil societies, making them attractive for sustainable business and investment.

Why Does This Matter?

• Policy Guidance: Countries use EPI and CCPI data to set targets, track trends, and refine environmental policies.
• Business and Investment: High scores signal a favorable environment for green investment and sustainable business operations.
• Public Health: Clean air, water, and effective waste management directly improve quality of life and reduce healthcare costs.
• Global Leadership: These nations serve as models for others striving to balance economic growth with environmental stewardship.

Summary point

As environmental challenges grow increasingly urgent worldwide, the achievements of these top 10 cleanest countries in 2025 offer both inspiration and a practical roadmap for sustainable development. Their success demonstrates that with visionary leadership, innovative technologies, and committed public participation, it is possible to safeguard natural resources, improve public health, and foster economic growth simultaneously.

By learning from their policies and practices, other nations can accelerate their own journeys toward a cleaner, greener, and more resilient future—ensuring a healthier planet for generations to come

Bahrain has swiftly enacted a remote work policy affecting 70% of government employees, a move prompted by escalating regional tensions and security concerns. The Civil Service Bureau (CSB) announced that this measure, effective immediately and until further notice, applies to all ministries and government agencies except for sectors that require physical presence due to the nature of their duties or emergency protocols.

The remaining 30% of staff, primarily in essential and emergency services, will continue to report to their workplaces to ensure uninterrupted delivery of critical public services.

This decision comes as part of Bahrain’s broader strategy to safeguard public health and safety while maintaining the continuity of government operations amid ongoing instability in the region. Ministries and agencies have been instructed to coordinate internally to ensure smooth workflow and operational efficiency under the new arrangement.

The CSB emphasized that the remote work directive aligns with national safety measures and will be continually assessed as the situation evolves, with further guidance to be provided as necessary.

Bahrain has been adapting to more flexible work models in recent years, supported by robust technological infrastructure and evolving labor practices. Employers are expected to clearly define remote work terms, ensure data security, and provide necessary equipment and IT support to remote staff.

The government’s proactive approach in activating remote work underscores its commitment to minimizing risks to employees and the public during periods of heightened caution, while leveraging advanced connectivity and digital tools to sustain essential services

The UK Foreign Office has issued a new travel advisory warning of potential disruptions due to escalating hostilities between Israel and Iran. The warning highlights the risk of rapid escalation and security threats across the wider region, which could lead to short-notice airspace closures, flight delays, cancellations, and other unexpected travel impacts.

Travelers are advised to:

• Monitor local and international media for the latest updates
• Stay vigilant and follow instructions from local authorities
• Check with airlines for current flight information before traveling

This alert comes as airlines suspend flights to the UAE and other Middle Eastern destinations amid rising tensions. American Airlines has suspended its only Middle East route, Flight AA120 between Philadelphia and Doha, Qatar, citing safety concerns. The suspension is in effect until June 22, with several flights already cancelled on June 18, 19, and 20.

United Airlines has also halted daily flights between Newark Liberty International Airport and Dubai as of June 19, stating it will resume service "when it’s safe," without specifying a return date. Passengers flying to the UAE are strongly advised to verify their flight status with their airline before departure.

The ongoing conflict has led to widespread airspace closures and airport shutdowns in the region. Israel’s Ben Gurion Airport remains closed indefinitely, and Iran has suspended flights to and from Khomeini International Airport. Neighboring countries including Iraq, Jordan, and Syria have also closed their airspace, causing major disruptions to international flight routes.

Travelers should prepare for potential delays and rerouted flights, with some airlines diverting flights through alternative hubs such as Vienna, Jeddah, or Frankfurt. The UK Foreign Office continues to monitor the situation closely and urges all travelers to exercise caution and stay informed as the situation develops.

Qatar Airways has issued a travel alert announcing that, effective June 22, 2025, several flights have been retimed to enhance connectivity and minimize disruptions across its global network. Some departure times may now be earlier than originally scheduled as part of the airline’s efforts to preserve operational reliability, network integrity, and resilience.

Passengers are strongly advised to verify their updated flight times ahead of travel via the official Qatar Airways website or the mobile app to ensure a smooth journey. The airline also urges travel agents to monitor their GDS queues closely for schedule changes and to promptly inform affected clients, ensuring bookings include accurate contact details for timely communication.

In addition to the flight retimings, Qatar Airways continues to comply fully with international aviation safety regulations, underscoring that passenger and crew safety remains the highest priority.

The flight schedule adjustments come amid broader strategic modifications in Qatar Airways’ Northern Summer 2025 schedule, which includes aircraft swaps, frequency changes, and seasonal service adjustments across Europe, Asia, Africa, and the Americas. Specific route changes include increased frequencies on some routes such as Doha to Bangkok and Entebbe, and reductions or cancellations on others, including seasonal cancellations on routes to Türkiye and adjustments on flights to Iran, Iraq, Jordan, Lebanon, and Syria, where some flights have been temporarily cancelled or rebooked with flexible options for passengers.

Passengers holding tickets for affected flights to or from these regions are permitted two free reissues within 21 days of their original travel dates, with flexible rerouting options to accommodate travel plans.

Qatar Airways thanks its passengers and partners for their understanding and cooperation as it implements these changes to maintain a reliable and safe travel experience worldwide.

Passengers are encouraged to stay informed by checking their flight status at qatarairways.com or by using the Qatar Airways mobile app for real-time updates. Qatar Airways remains committed to delivering seamless and safe travel for all its customers.

Major international airlines are continuing to divert their flights to avoid Middle Eastern airspace after the recent U.S. military strikes on Iranian nuclear facilities, escalating regional tensions and disrupting global air travel.

Flight tracking data from FlightRadar24 shows that airlines including United Airlines and American Airlines are steering clear of high-risk zones encompassing Iran, Iraq, Syria, and Israel. Instead of the usual direct routes, flights are now detouring north over the Caspian Sea or south through Egypt and Saudi Arabia. These longer paths increase fuel consumption, crew expenses, and overall operating costs for airlines.

The rerouting follows a series of military escalations beginning June 13, when Israel launched retaliatory strikes against Iranian targets. The situation intensified after the U.S. conducted coordinated airstrikes on three key Iranian nuclear sites Fordo, Natanz, and Isfahan using advanced bunker-buster bombs. These strikes, described by President Trump as “completely obliterating” Iran’s nuclear enrichment capabilities, have heightened fears of further conflict and retaliation.

In response to the volatile security environment, airlines have suspended flights to several Middle Eastern destinations. American Airlines halted services to Qatar, United Airlines paused flights to Dubai, and Israel’s main carriers El Al, Arkia, and Israir have suspended both commercial and rescue flights until at least June 27.

 Israel has closed its airspace, though land borders with Egypt and Jordan remain open, leaving tens of thousands of travelers stranded. The Israeli Tourism Ministry is facilitating their departure through alternate routes such as transit via Amman or ferry services to Cyprus.

The ripple effects extend beyond flight disruptions. Several countries have initiated evacuation efforts for their citizens. Japan successfully evacuated 21 people from Iran overland to Azerbaijan, marking its second such operation in recent days. New Zealand announced plans to deploy a Hercules military transport aircraft to the region to assist with potential evacuations.

Aviation safety organizations like Safe Airspace have warned of increased risks to commercial flights operating near the conflict zones, urging caution as missile and drone attacks continue to threaten the region. Airlines are now treating airspace over multiple Middle Eastern countries as restricted, even those not directly involved in the conflict, impacting long-haul flights connecting Europe, Asia, and Africa.

The U.S. strikes have triggered a complex political fallout. While some U.S. politicians praised the military action, others criticized it for bypassing congressional approval. Iran has vowed “everlasting consequences” and retains capabilities for missile retaliation, potentially targeting U.S. military bases and critical energy transit routes like the Strait of Hormuz, through which a significant portion of the world’s oil supply passes.

Recent Iranian missile salvos targeting Israeli cities underscore the risk of sustained regional escalation.
This evolving crisis has forced airlines worldwide to balance operational challenges with passenger safety amid one of the most volatile periods in Middle Eastern aviation history.

Israel’s main international airport, Tel Aviv’s Ben Gurion Airport, has been closed for over six days, marking the longest shutdown in Israel’s 76-year history due to the ongoing conflict with Iran. The closure began shortly after Israel launched strikes on Iranian military and nuclear enrichment sites on the night of June 12-13, 2025, prompting the closure of airspace across the Middle East.

The airport’s shutdown has created significant travel disruptions, stranding thousands of Israeli citizens abroad and foreign visitors in Israel. Israeli flag carrier El Al was authorized on June 17 to operate recovery flights to bring citizens home. The airline reported its first repatriation flights landed on June 18 and announced that over 70,000 people had registered for these flights.

Recovery flights are being gradually operated from destinations including Larnaca, Paphos, Budapest, Athens, Milan, Rome, and London (Luton), subject to government approval.

The closure follows an intensification of military operations in the region. Israeli airstrikes targeted key Iranian nuclear and military sites, including a centrifuge manufacturing workshop in Isfahan province and military installations in Shiraz and Khuzestan province. The International Atomic Energy Agency (IAEA) confirmed strikes on Iran’s Natanz nuclear site, noting no radiological consequences.

Iran retaliated with multiple missile and drone attacks on Israeli cities, including Tel Aviv, Haifa, and Jerusalem, resulting in casualties and damage to civilian infrastructure.

The conflict has escalated to include proxy groups such as Hezbollah and the Houthis, who have launched attacks on Israeli territory. The United States has been involved in defensive operations, shooting down Iranian missiles and drones, and on June 21, it conducted strikes on three Iranian nuclear sites, further intensifying the conflict. President Donald Trump has reviewed military options but has delayed further action, awaiting Iran’s response to diplomatic pressure.

Major international airlines, including U.S. carriers Delta and United, have suspended flights to Israel due to the airspace closure and security concerns. The last full closure of Ben Gurion Airport was on October 1, 2024, following a missile attack from Iran, but the current shutdown is unprecedented in length and impact.
Israeli authorities have indicated preparations to resume outbound flights with strict passenger limits, prioritizing humanitarian and security-related travel.

The airspace was temporarily reopened on June 22 to facilitate repatriation flights, reflecting ongoing efforts to restore normalcy amid the conflict.

This prolonged airport closure underscores the severe disruption caused by the Israel-Iran conflict, which has rapidly escalated since mid-June 2025, involving extensive military strikes, drone activity, missile barrages, and international diplomatic maneuvers. The situation remains volatile, with the potential for further escalation affecting regional stability and global security.