I would need to see average global surface temperature being uncoupled from atmospheric CO2 levels, sustained over a long period of time. Given that we have hundreds of thousands of years of climate records [0], that seems like a tall order.

One cold spell does not disprove global warming. While Dallas might be experiencing abnormally low temps, Jacksonville's seeing uncharacteristic highs (86F today).

[0] https://www.ncdc.noaa.gov/global-warming/temperature-change