Let's fix the math.

Amount of energy consumed from global data centers: 205 terawatt-hours. [0]

Amount of water in the oceans: 1,386,000,000 (km3)~= 1.386*10^21kg[1]

water has a specific heat capacity of: 4,200 J/kg°C [2]

Energy/HeatCapacity/AmountOfWater = 1.268×10^-7 degrees Celsius

[0]: https://energyinnovation.org/2020/03/17/how-much-energy-do-d... [1]: https://www.usgs.gov/special-topic/water-science-school/scie... [2]: https://www.bbc.co.uk/bitesize/guides/z2gjtv4/revision/5