Australia's Great Barrier Reef is dying and it is dying fast. Located off the coast of North Queensland, two-thirds of the corals in the northern part of this natural wonder have died because of a combination of global warming, coral bleaching, and other factors.

The Great Barrier Reef is the world's largest collection of vivid coral reefs, but because of threats posed by human-caused climate change, it is becoming lifeless and bleak.

Before and after photos show what was once an incredible ecosystem filled with life that has now been severely impacted by multiple factors including a mass bleaching event in 2016 and 2017. The world's largest reef system is struggling to recover and we need to do all we can to save it.

Here are 20 sad photos of Australia's Great Barrier Reef.

20 The Great Barrier Reef Contains The World's Largest Collection Of Coral Reefs

The Great Barrier Reef contains the world's largest collection of coral reefs, with 400 types of coral, 1,500 species of fish and 4,000 types of mollusk, according to UNESCO. People from all over the world have swum, dived, snorkeled and explored this 1,430-mile natural wonder filled with bright colors and a collection of underwater creatures.

19 Australia's Great Barrier Isn't What It Used To Be

Sadly, this stunning array of vivid coral and the abundance of marine life that call this place home is not what it used to be. According to scientists, the Great Barrier Reef is dying at an alarming rate thanks to climate change, rising sea temperatures and tourists accidentally damaging these precious areas.

18 The Loss Of Coral Is At An All-Time High

A 2017 graphic released by the Australian Government's Great Barrier Reef Marine Park Authority revealed shocking numbers of dead coral across four major sections of the Great Barrier Reef, which include the Far North, North, Central, and South. The percentage of dead coral for each region was 26%, 67%, 6%, and 1% respectively. Since then, these numbers have only gotten higher.

17 What Is Rapidly Killing Parts Of The Great Barrier Reef?

According to The Washington Post, in 2016, a spike in ocean temperature caused a huge "bleaching" event that resulted in vivid colored corals turning a "sickly white." As temperatures continue to rise, scientists believe another bleaching will take place within the next decade or two. Corals cannot tolerate large temperature changes.

16 Human Activities Are Damaging This Natural Wonder

According to The Atlantic, the vast bleaching that killed these corals was caused by "human-caused global warming." "The accumulation of heat-trapping pollution in the atmosphere has raised the world's average temperature, making the oceans hotter and less hospitable to fragile tropical coral," the site stated.

15 Before And After Pictures Are Shocking

A new study in the journal Nature reported that chances of these corals making a comeback are sadly, very slim. "The chances of the northern Great Barrier Reef returning to its pre-bleaching assemblage structure are slim given the scale of damage that occurred in 2016 and the likelihood of a fourth bleaching event occurring within the next decade or two as global temperatures continue to rise."

14 Coral May Never Recover

Since the mass bleaching in 2016 and 2017, studies have unfortunately shown that baby coral in the Great Barrier Reef have declined by a whopping 89%. These back-to-back bleaching events have gravely hurt coral reefs. Scientists expect the coral to recover over the next 5-10 years only if another bleaching event doesn't occur, CBS News reported.

13 Temperatures Are Rising

Australia's ocean have risen in temperature by one degree over the last 110 years. This may not seem like much, but it is devastating to the Great Barrier Reef. According to Coral Reed Studies, corals inhabiting tropical coral reefs are thermally sensitive, which means they can only tolerate small changes in temperature. So, as the water warms, the intensity of coral bleaching increases.

12 Divers And Tourists Aren't Realizing Their Impact

While Australia welcomes tourists to take a dive and swim through the Great Barrier Reef, inexperienced divers who aren't aware of the rapid loss of coral end up damaging it even more. Divers often brush against coral or take a piece of it home as a souvenir. Boats taking tourists to dive sites can also rip apart shallow groups of coral, according to The Travel.

11 The World's Largest Reef System May Vanish

Mark Eakin, study author, and coordinator of the US National Oceanic and Atmospheric Administration's Coral Reef Watch stated that coral reefs are way more sensitive to heat stress than we realized, adding that "climate change threatens the diversity that is the hallmark of coral reefs." The increase in marine heat is all our fault, too.

10 "That's Just Like Losing Half Of The Trees In The Appalachian Or Rocky Mountains"

Mark Eakin told CNN that it was surprising how little heat stress was needed to cause such a detrimental loss of coral in the northern Great Barrier Reef, comparing it to "like losing half of the trees in the Appalachian or Rocky Mountains in just two years," he stated. And its recovery is extremely unlikely unless we reduce the carbon dioxide in the atmosphere.

9 Multiple Threats To The Biggest Living Structure On Our Planet

According to the World Wildlife Fund, another factor that is heavily damaging the Great Barrier Reef is farm pollution. "It smothers corals and seagrass beds and denies them sunlight, drives crown of thorn starfish and makes coral more vulnerable to bleaching," adding, "nitrogen run-off from farms can also lead to algal blooms, which starfish larvae feed on, promoting population explosions."

8 Industrialization Is Hurting This World Heritage Site

Another large factor that is killing the Great Barrier Reef besides coral bleaching and farm pollution is industrialization. World Wildlife Fund explains that "port expansion leads to dredging of the seafloor, increased shipping traffic, and a range of other impacts on the delicate coastal and marine environment of this World Heritage Area."

7 There's A Decline Of New Corals Settling On The Reefs

The mass bleaching of the Great Barrier Reef in 2016 and 2017 has not only killed many of the adult coral, but researchers are starting to witness a significant decline in new corals settling on the reef, according to The New York Times. This is devastating to this ecosystem that is relying on baby coral to help recover from the mass bleaching, with time left to save it is growing shorter and shorter.

6 Understanding Just How Vast This Ecosystem Is

To get a better sense as to how large this coral reef ecosystem is for those who aren't aware, it is roughly the same area as Italy, Japan, Germany or Malaysia. With 3,000 coral reefs, 600 continental islands, 133 varieties of sharks and ray and 1,625 types of fish, the Great Barrier Reef is as big as 70 million football fields, according to Australian Government's Great Barrier Reef Marine Park Authority.

5 Losing All Its Colors And Life

It's truly shocking to see photos of the Great Barrier Reef from ten years ago and today. Because of a combination of severe coral bleaching, the damage done by Cyclone Debbie in 2017, and tourists neglecting coral and unintentionally harming it, what was once a beautiful and colorful part of our world is vanishing before our eyes.

4 Bleaching Has Eased In The Southern Parts

Thankfully, the damage done to the Great Barrier Reef hasn't affected it entirely. While nearly all the corals have died in the northern part, the impact of bleaching eases as you go to the south, and reefs in the central and southern regions were not affected as badly, and are recovering. This shows that there is still much to see throughout the Great Barrier Reef, but hopefully, tourists are more careful.

3 What Will Happen Now?

David Wachenfeld, Director for Reef Recovery at the Great Barrier Reef Marine Park Authority believes that the process to replace dead coral, mostly in the northern areas will be slow, giving an estimate of 5-10 years. However, as long as conditions such as water temperature remain "conductive to recovery" these corals should be on track to making a comeback.

2 We Must Save Surviving Coral

We must focus on saving the coral that has survived the massive bleaching and global warming. Terry Hughes, study author, and director of the Australian Research Council Center of Excellence for Coral Reef Studies at James Cook University said, "That still leaves a billion or so corals alive, and on average, they are tougher than the ones that died... We need to focus urgently on protecting the glass that's half full, by helping these survivors to recover."

1 What We Can Do To Help

There is a lot people can do to help the reef. According to Reef Teach, people should start supporting conservation organizations and marine parks through donations, help educate others about what is going on in the Great Barrier Reef and climate change, stop using plastic, and save energy in your own home.