The higher it is, the more intense the radiation is, just like a hot bar of metal emits much more
heat than a cold one.
On the other hand, increased atmospheric CO2 is expected to cause global warming, and warmer ocean waters would release more CO2 into the atmosphere (somewhat as a warm soda - water bubbles more fiercely
than a cold one when it is opened).
In addition, the development of mosquito larvae is faster in warm
climates than cold ones, and thus with global warming, the mosquito will become a transmitting adult earlier in the season.
An El Niño results from a warm ocean, which is less able to absorb carbon
dioxide than a cold one; what's more, an El Niño has the potential to cause droughts in some regions, either inducing wildfires or restricting the growth of vegetation, so limiting its capacity to photosynthesize.
(Warm potatoes absorb the dressing better
than cold ones.)