http://www.geoengineeringwatch.org/is-whole-solar-system-warming/
“Other planets are warming
“[E]vidence that CO2 is not the principle driver of warming on this planet is provided by the simultaneous warming of other planets and moons in our solar system, despite the fact that they obviously have no anthropogenic emissions of greenhouse gases. Mars, Triton, Pluto and Jupiter all show global warming, pointing to the Sun as the dominating influence in determining climate throughout the solar system.” (Ian McClintock)
Yet the chart on the same page indicates that the while the planets are heating up, the sun cycle is at a low for intensity. Therefore, something else with a heat source is causing all the planets temperatures to increase.
“Only Pluto and Neptune are exhibiting increased brightness. “
These outer planets would be the first to experience changes should a large planet enter the solar system. Its presence would cause global warming (mass animal die offs), pole shifts and gravitational issues with all the planets near it.