USA  has only stated what many feel about climate change.
YES ....the climate is changing.....as has always changed...and will continue to change.
What is at issue...is just how much of the change can be attributed to man made pollution.
Earth's orbit around the sun is slowly deteriorating....sun is cooling.slowly as well.
Rate of spin of the Earth  has declined....which also affects the tilt of Earth on it's axis.

Tectonic plates continue to migrate(sometimes called continental drift)...causing some seaways to deepen/cool, and others to become more shallow/warm.  The effect on winds, temperatures, precipitation  are  ongoing.  Most of Canada was covered by a ONE MILE THICK PLATE OF ICE...on one , if not more than one time period in our past.

These ongoing forces of nature are the major reasons for climate change.....pollution by man can't be allowed to continue..but how much this has changed  climate has never been  honestly established