If the world is generally getting hotter, would a higher temperature affect the buoyancy of objects in the air (e.g., helium balloons)

Hot air balloons float by heating the air inside an inflatable compartment. Consider such a balloon which has an inflatable compartment of maximum volume 2755 m3 and a basket with passengers of total mass 280 kg. a) How hot, in degrees Celsius, would the air inside the balloon have to get in order for the balloon to lift off the ground? Assume the molar mass of air is 28.97 g/mol and its density is 1.20 kg/m3.  b)When the balloon reaches the highest point of its flight (around 2000 m), the air pressure has dropped to 80% of the pressure at ground level, and the density has dropped to 85%. What temperature, in degrees Celsius, must the air in the balloon be to keep it floating at this altitude?

A basketball is pressurized to a gauge pressure of PG = 55 kPa when at the surface of a swimming pool. (Patm = 101 kPa). The ball is then submerged in the pool of water which has a density ρ = 1000 kg/m3. Assume the ball does not change in mass, temperature, or volume as it is submerged. Calculate the absolute pressure inside the basketball in kPa when it is at the surface.  Write an equation for the pressure difference ΔP between the inside and outside of the ball when it is submerged a distance y below the surface of the water.  Solve the pressure equation for the depth (in meters) at which the pressure difference between the inside and outside of the ball will become zero. At this depth the pressure inside the basketball is the same as the pressure outside the ball.

What is gas density, if under pressure of 105 Pa, its molecules move at a speed of 300 m/s? /Give the answer in [kg/m3] /