However, they conceded that it was purely speculative, and several other scientists have cautioned against linking these bursts to possible alien intelligence. .
Other scientists – including Stephen Hawking – have cautioned that making contact with aliens could be dangerous, but as Shostak points out Seti isn't broadcasting messages, it is just listening.
Scientists studying the risks facing human explorers of Mars have cautioned that windblown dust, pervasive on the arid planet, threatens to abrade, clog and corrode vital spacecraft systems.
I have cautioned myself against that.
Yet scientists have long cautioned that the brain is not a filing cabinet, storing memories in a way that they can be pulled out, consulted and returned intact.
Climate scientists and activists cautioned that while the agreement was unexpectedly ambitious, the measures did not go far enough.
Scientists have begun questioning that assumption.
For more than 20 years marine scientists have issued cautions about the reef, and have associated these cautions with human-induced climate change.
Scientists not involved in the work welcomed the finding, but cautioned that human trials of teixobactin would be key.
