More than half of the birds in Washington are at risk of extinction because of climate change. That's according to a new national report from the Audubon Society, which gives detailed analysis of climate effects on about 600 species of North American birds.

It's based on more than 140 million observations of birds across the US, Mexico and Canada. Audubon scientists looked at the likely effects of sea-level rise, urbanization, drought, extreme spring heat, increased fires, heavy rain and other factors.

But it doesn't just spell out a doomsday scenario (世界末日).Instead, it offers a range of effects and warming, depending on how much carbon humans add to the atmosphere.

"It is truly an existential threat (威胁), not only to birds but to people,” said Doug Santoni, board chair of Audubon Washington, who looked into the report as soon as it came out.

Santoni says he was struck to see the vulnerability (脆弱)of a common “ backyard bird" , the dark-eyed junco. It's one that many first-time birders become familiar with as they learn how to identify species based on their markings and other traits. Currently in Washington, you can count on juncos to show up at your feeder, year round. Extreme spring heat, increased fires and heavy rain are the kinds of changes that will force birds like these north, or kill them off if they fail to adapt.

Trina Bayard, director of bird conservation at Audubon’s Washington chapter, says, "It's certainly a very serious warning report," but adds that there’s still hope. “If we can stabilize current temperatures and decrease our emissions (排放), we can really reduce the effects to these birds …that's very motivating. ”

【小题1】What can we know about the new report?

A．It analyses the species of birds in detail.

B．It's issued by watching 600 bird species.

C．It shows the end of North American birds.

D．It reports the threat some birds are facing.

【小题2】What may Santoni probably agree with?

A．Climate change is a threat only to birds.

B．It's too late to take action to save the birds.

C．The current situation of the birds is worrying.

D．It's common that birds are affected by climate change.

【小题3】Which of the following can help these birds according to Trina?

A．Lowering present temperatures.

B．Reducing our daily emissions.

C．Making them adapt to climate change.

D．Encouraging people to protect them.

【小题4】What can be the best title for the text?

A．Climate change threatens many Washington bird species.

B．A new report about 600 species of North American birds.

C．Different attitudes towards the situation of bird species.

D．Climate change makes different kinds of species at risk.