How humans and climate change affects wildfires

Fanning the Flame

(Updated November 2021)

Despite the nearly 16,000 km (~10,000 miles) distance between them, recent fires in the Amazon rainforest and Australia are intimately linked— by climate change.

Bushfire smoldering in the Australian Outback.

Fires in the Amazon are almost always intentionally set by humans. Their goal is to clear swaths of the rainforest for agricultural development, and this purposeful damage to one of the world’s largest carbon sinks is contributing to increasingly dry climates around the world. The Amazon rainforest actively absorbs an enormous amount of carbon that has been released into the atmosphere. When the Amazon burns, it transforms from being a carbon sink to a carbon source.

Wildfires have become more frequent and intense as a result of global climate change. These effects have been realized in Australia, as record-breaking heat and drought conditions have fueled devastating wildfires that burned through the beginning of 2020.

While slash and burn practices in the Amazon have direct implications for future global CO2 levels, this is but one of the countless contributors to the climate change effects felt in Australia. However, the relationship between fires in the Amazon and Australia demonstrates how actions on one side of the planet can cause devastating consequences on the other—and shines a light on the complex, global nature of this environmental crisis.

Brazil – Productive reforestation through the implementation of agroforestry systems: vegetable beds (lettuce, cauliflower, tomato, etc.) between tree beds.

Burn It Down

Wildfires are a natural part of many ecosystems, such as in Australia, but there’s nothing natural about most fires in the Amazon. The Amazon is not supposed to burn—fire is not part of the natural system, and nothing is adapted to fire. Natural fires can occur in the Amazon, but they are typically small and extinguished quickly by rain.[1]

The vast majority of fires in the Amazon are started by farmers to clear land for agriculture and pasture. This practice is not new, but there is a difference between modern and classical methods. Modern-day Amazon farmers set out to completely flatten the forest with their slash-and-burn practices.

In contrast, ancient relatives appear to have practiced something similar to agroforestry, a method where crops are grown among the trees to keep the soil healthy and biodiversity high.[2]

The use of more sustainable land clearing methods by modern farmers could help reduce the need to clear more land in the future. Amazon soil is old and weathered, acidic, infertile, and easily compacts due to radiation from the sun. When farmers cut and subsequently burn vegetation in the Amazon, it does temporarily enrich the soil. However, these nutrients are leached or become unavailable after just a few years.[3] Farmers are ultimately driven to burn new areas of forest, thus intensifying the need for deforestation.

BrazilAerial view of a large monoculture soy field eating into the tropical rainforest. Monocultures lower biodiversity in a given area in favor of greater crop yields.

Wiping Out Years of Progress

Positive stories about the environment are often few and far between, but they do exist. The reduction of the hole in the ozone layer over the Antarctic is perhaps the most celebrated success of environmental policy. Another success story that took shape in recent decades was the reduction of deforestation in the Amazon, but that is unraveling quickly.

Deforestation in the Amazon rose sharply from the 1970s to the early 2000s, but this trend began to reverse around 2004 after the Brazilian government introduced new regulations and policies that targeted deforestation.  By 2012, the annual deforestation rate was 80 percent lower than the average rate between 1995 and 2006.[4]

Rates of deforestation in the Brazilian Amazon—where the majority of the rainforest resides—began climbing again after reaching a low point in 2012.

This increase in deforestation has accelerated recently, as data released by the Brazilian government in November 2019 revealed a 30% increase in the amount of land deforested between August 2018 and July 2019 (9,762 km2, 2.4 million acres) compared to the same period the year before.[5] It’s this drastic increase in deforestation from year to year that caught the world’s attention in 2019.

Brazil – June 18th, 2018: The current president-elect, Jair Bolsonaro during participation in the Unica Forum. (Photo Credit: Marcelo Chello /

Controversial New Policies

The uptick in Amazon deforestation coincides with the election of Brazil’s new president, Jair Bolsonaro. Bolsonaro is a strong advocate for using resources in the Amazon rainforest to boost Brazil’s economy. While campaigning for president, Bolsonaro promised to open up the Amazon rainforest to activities such as agriculture and mining. This promise has been kept, but not without criticism from within Brazil and throughout the international community, especially after images of smoke rising from the rainforest spread like wildfire across the internet in late 2019.

Bolsonaro is unlikely to change his views on the country’s agricultural practices, primarily because he does not want to negatively impact Brazil’s economy. In November 2019, he called the fires “cultural” and stated, “deforestation and fires will never end.”[6] Deforestation rates in the Amazon continue to accelerate. In January 2020, the amount of land destroyed was double that of January 2019.[7]

BrazilAerial view of deforestation. Rainforest being removed to make way for palm oil and rubber plantations.

Armageddon in Australia

Unlike the Amazon rainforest, naturally occurring fires are relatively common in Australia. However, the 2019-2020 Australian bushfire season was extraordinarily devastating. Through the end of January 2020, an estimated 11 million hectares (27.2 million acres) of land across Australia burned—an area roughly the size of Virginia—and 33 people died. Over 2,000 homes were destroyed in New South Wales (NSW), the hardest-hit state.[8]

Fires have taken an unfathomable toll on wildlife in the land Down Under. Images of burnt, thirsty koalas and kangaroos rushing away from flames shook the world. It is estimated that over one billion–yes, billion-animals were killed in the fires.

Koala Catastrophe: An estimated 25,000 koalas were killed when fires raced across Kangaroo Island on 1/9/2020.[8]

Feeling The Heat

It's no coincidence the fires occurred at the same time many parts of Australia were in drought conditions, and when an extreme heatwave gripped the nation. Australia’s six hottest days ever were recorded in December 2019, while average rainfall across the country was at a record low.[9]

This severe weather occurred throughout all of 2019, as Australia’s area-averaged mean temperature was 1.52°C above the 1961–1990 average, breaking the previous record of +1.33°C set in 2013.[10]

To make matters worse, 2019 was also the driest year on record, with only 277.66 mm of precipitation (nationally-averaged), well below the previous record of 314.5 mm set in 1902.[10]

The record-breaking heat in 2019 continued a trend— Australia is getting hotter. All the years since 2013 have been amongst the ten warmest on record for Australia. Only one of the top ten warmest years (1998) occurred before 2005.[10]


Were Arsonists To Blame?

Australia’s intense fire season was a product of exceptionally dry and hot conditions, but what started most of the fires? While some may claim arsonists were to blame, government officials point to dry lightning storms as the initial cause of the vast majority of fires. In NSW, it was estimated that only 1% of the land burnt was tied to arson.[11]

Government Action

There are numerous other contributors to climate change besides fires in the Amazon, so it is not fair to pin all the blame of Australia’s wildfires on Brazil’s policies. All countries, including Australia, contribute to climate change. Weak environmental policies are also not isolated to Brazil.

Environmentalists have criticized Australian Prime Minister Scott Morrison for his government’s stance on climate change. Australia is not on track to meet its commitment to the Paris Climate Agreement, and the country had the lowest climate policy rating in the 2020 Climate Change Performance Index.[12]

Countries such as Sweden and Denmark have been successful in enacting strategies to reduce their greenhouse gas emissions and increase their use of renewable energy.

However, even if there are countries doing everything they can to reduce their impact on the environment, it may not be enough to halt the impacts of climate change. We need every country on board.


What Can You Do?

The underlying causes of fires in the Amazon and Australia are different—intentional fires are set in the Amazon, while climate change is to blame in Australia. But both of these causes are a product of environmental policy, and change can be made by local citizens through voting and applying pressure on the government to act.

Other actions you can take to help fight climate change include reducing your greenhouse gas emissions, investing in renewable energy, planting trees, and implementing a climate-friendly diet.

You can also drive change by investing in businesses with sustainable missions and products. Some businesses and industries are notorious for emitting enormous amounts of CO2 each year, but more and more businesses are recognizing the importance of going green.

Xylem has a deep commitment to sustainability and solving the world’s water challenges. Efforts to minimize our environmental footprint have resulted in Xylem’s inclusion on Fortune’s 2019 "Change the World" list for a second year running.

Make a Difference by Supporting These Causes:

Rainforest Action Network’s Protect-an Acre Program (PAA): Distributes grants that help secure protection for millions of acres of land in the Amazon.

Amazon Watch: Partners with indigenous and environmental organizations for human rights and the preservation of the Amazon.

One Tree Planted: Non-profit environmental charity on a mission of global reforestation.

Australian Red Cross: Collecting donations to help those impacted by the bushfires.

Wires (NSW Wildlife Information, Rescue and Education Services Inc.): Australia’s largest wildlife rescue organization. Rescuing and caring for wildlife for over 30 years.

Koala Hospital: The Koala Hospital is a licensed Wildlife Rehabilitation Facility carrying out on-site procedures.

Australia Zoo, Wildlife Warriors: Established in 2002 by Steve and Terri Irwin as a way to involve other caring people in the protection of wildlife.

1 | National Geographic, What the Amazon fires mean for wild animals

2 | Ensia, Ancient Amazon societies managed the forest intensively but sustainably

3 | Yale School of Forestry and Environmental Studies, Land Use and Agriculture in the Amazon

4 | National Geographic, See how much of the Amazon is burning, how it compares to other years

5 | Reuters, Brazil Amazon deforestation soars to 11-year high under Bolsonaro

6 | Washington Post, Brazil’s Bolsonaro calls Amazon  deforestation ‘cultural,’ says it ‘will never end’

7 | Reuters, Brazil environment agents surprised by  deforestation through rainy season

8 |BBC, Australia fires: A visual guide to the bushfire crisis

9 | The Guardian, Australia records worst December fire  conditions after its hottest, driest year

10 | Australia Bureau of Meterology, Annual climate statement 2019

11 | ABC, The truth about Australia's fires — arsonists aren't responsible for many this season

12 | Climate Change Performance Index (CCPI), Results 2020


1 Responses to this article

The maintenance of environmental balance is very important.


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