Prince Harry and Meghan Markle Follow Greta Thunberg on Instagram: 'There is a Ticking Clock to Protect Our Planet'

Prince Harry and Meghan, Duchess of Sussex followed teen activist Greta Thunberg on Instagram Monday in an effort to highlight the work of environmental campaigners.

Harry also dismissed the idea that environmental damage is a necessary by-product of economic growth in a post shared by more than 140,000 Instagram users by 11.30 a.m. BST (6.30 a.m. ET).

The royal couple regularly delete all their followed accounts and replace them with groups involved in particular social causes. In May, they followed several accounts involved in mental health campaigning.

For July, the couple's sussexroyal account followed charities including the African Parks network, Rhino Conservation Botswana and intersectional youth climate movement Zero Hour. They also followed the accounts of Thunberg and billionaire philanthropist Mike Bloomberg.

A sussexroyal post about the social media effort read: "There is a ticking clock to protect our planet—with climate change, the deterioration of our natural resources, endangerment of sacred wildlife, the impact of plastics and microplastics, and fossil fuel emissions, we are jeopardizing this beautiful place we call home."

Prince Harry himself called out "deeply ingrained" arguments that environmental damage is a "necessary by-product" of economic growth. "It has been considered part of the natural order that humankind's development comes at the expense of our planet," he is quoted as saying in the post. "Only now are we starting to notice and understand the damage that we've been causing."

The duke continued: "With nearly 7.7 billion people inhabiting this Earth, every choice, every footprint, every action makes a difference."

Thunberg, 16, shot to fame in 2018 after campaigning for more action on climate change outside the Swedish parliament. "School strike" climate protests inspired by the teenager have taken place around the world. She was nominated for the Nobel Peace Prize in March.

Several members of the British royal family share Harry and Meghan's support for environmental causes. Prince Charles, for example, co-authored an educational book for adults on climate change in 2017.

Harry has advocated for action against climate change on several occasions. He recently encouraged young people to get involved in climate causes at a garden party, for example.

But the young duke has been accused of hypocrisy over his own carbon footprint. The Sun called Harry out for using a private helicopter just days before telling young people to "wake up" and act on climate change at an event in London.

Although the royal family reduced its domestic carbon footprint last year, an increased reliance on large aircraft for international engagements saw the family's total greenhouse gas emissions rise by 3 percent, according to official financial documents.

Prince Harry, Meghan Markle, Instagram
Prince Harry, Duke of Sussex and Meghan, Duchess of Sussex look on during the pre-game ceremonies before the MLB London Series game between Boston Red Sox and New York Yankees at London Stadium on June 29 in London, England. Dan Istitene - Pool/Getty