Identifying Logical Fallacies in Debate

In a recent debate about climate change, Speaker A stated, "If we continue to ignore the warnings from scientists about rising sea levels, soon we will be underwater. Therefore, we must take immediate action to combat climate change." Speaker B protested, interjecting, "You can't believe Speaker A; they want to impose heavy taxes on everyone to fund their climate initiatives!"

This exchange illustrates a specific logical fallacy committed by Speaker B in response to Speaker A's argument. Which logical fallacy does Speaker B's argument exemplify?