Democratic presidential candidate and former Vice President Joe Biden released a climate-change proposal on Tuesday.

In at least three instances, Biden's plan appears to directly copy language from letters and websites for other climate-change advocacy organizations.

Biden's 1988 presidential campaign largely failed because of plagiarism accusations after he copied a speech from a UK member of parliament.

Visit Business Insider's homepage for more stories.

Democratic presidential candidate and former Vice President Joe Biden released on Tuesday a comprehensive proposal to combat global climate change, adding to the mix of candidates who have made rolling back dangerous emissions a central tenet of their campaigns.

But multiple sentences in Biden's proposal appear to lift passages from letters and websites for different organizations. The copied sentences are particularly notable because of Biden's past history of plagiarism, which played a major role in tanking his 1988 presidential campaign.

Read more: Joe Biden is running for president in 2020. Here's everything we know about the candidate and how he stacks up against the competition.

The potential plagiarism instances were first flagged by Josh Nelson, the vice president of Credo Mobile, a telecommunications company that also raises money for liberal activist groups and causes. INSIDER found another instance as well.

In Biden's plan, the campaign wrote about carbon-capture technology:

"Carbon capture, use, and storage (CCUS) is a rapidly growing technology that has the potential to create economic benefits for multiple industries while significantly reducing carbon dioxide emissions."

But in a letter that BlueGreen Alliance Executive Director Kim Glas sent to the Senate Committee on Environment and Public Works, the sentence is virtually the exact same:

"Carbon capture and sequestration (CCS) is a rapidly growing technology that has potential to create economic benefits for multiple industries while significantly reducing carbon dioxide (CO2) emissions."

Another instance of copied lines appears where the Biden campaign wrote about its goals regarding carbon capture:

"Biden's goal is to make CCUS a widely available, cost-effective, and rapidly scalable solution to reduce carbon emissions to meet mid-century climate goals."

That line is almost identical to the "our work" section of the website for the Carbon Capture Coalition's Center for Climate and Energy Solutions:

"Its goal is to make carbon capture, use and storage (CCUS) a widely available, cost-effective, and rapidly scalable solution to reduce carbon emissions to meet mid-century climate goals."

A third example appears in a description of water infrastructure. Biden's plan describes US sewage systems:

"The average American sewage pipe is 33 years old, with many pipes dating back 50 or even 100 years."

The clean-water advocacy group American Rivers has on the infrastructure section of its website:

"As a result, the average American sewage pipe is 33 years old, with many pipes dating back 50 or even 100 years."

Read more: Flashback: Joe Biden's first presidential run in 1988 cratered amid multiple instances of plagiarism

The Biden campaign told INSIDER, "Several citations were inadvertently left out of the final version of the 22-page document. As soon as we were made aware of it, we updated to include the proper citations."

Biden's 1988 presidential campaign failed in part because of accusations of plagiarism. In one instance, Biden copied a speech from a UK politician who claimed to have been the first in his family to graduate from college, while the then-Delaware senator actually had several relatives who had earned degrees.

Biden also came under scrutiny for plagiarizing lines from a law journal while at Syracuse University.

"My intent was not to deceive anyone,'' Biden wrote upon being disciplined in law school. ''For if it were, I would not have been so blatant.''