Clause 4 refers to international commitments. I won't speak for Ms. May, but I don't think the objective is to change those international commitments. It's simply to reinforce them. The way the bill is drafted, it refers to those commitments, which, as the preamble indicates, include joining the international effort to enhance efforts to take immediate action to minimize temperature increase. The amendment would refer to those obligations specifically, but wouldn't actually change them.
On May 26th, 2021. See this statement in context.