The main danger to Earth *Could be* if there were any even miniscule change in the Orbit of Mars -- unlikely though.
One of Mars's moons (Phobos) in any case is destined to collide into the planet (although by the time this happens the Earth will long since have become totally uninhabitable for Humans).
The sun will in the next few million years become about 10% brighter and hotter -- normal evolution for a star of this type -- absolutely 100% normal behaviour -- nothing to do with any man made phenomena - but even this increase makes the planet totally UNINHABITABLE for humankind.- Not to worry -- we've plenty of time to ensure we can colonize other places before Earth finally becomes unsuitable.
(Earth will actually live for another 4 Billion years before the Sun finally dies - but as above the planet will become uninhabitable LONG before that -- current estimates that we have around 500,000 years to go).
Phobos collision with Mars in about 10 million years Phobos Might Only Have 10 Million Years to Live
(Phobos orbits close to the Roche limit which might cause it to shatter before actually colliding with the planet -- but this would present more of a danger to Earth -- due to the large numbers of particles being scattered about in Random orbits)
Roche limit : Roche limit - Wikipedia, the free encyclopedia