The past decade has been the hottest ever recorded globally. 2019 was either the second or third warmest year on record depending on how you measure it and 2020 is break the records too.
Every decade since 1980 has been warmer than the preceding decade, with the period between 2010 and 2019 the hottest yet since worldwide temperature records began in the 19th century. The increase in average global temperature is rapidly gathering pace, with the last decade up to 0.39C warmer than the long-term average, compared with a 0.07C average increase per decade stretching back to 1880. The past six years, 2014 to 2019, have been the warmest since global records began, a period that has included enormous heatwaves in the US, Europe and India, freakishly hot temperatures in the Arctic, and deadly wildfires from Australia to California to Greece.
You can find more details from Carbon Brief here. State of the climate: 2020 set to be first or second warmest year on record.
So why is this happening?
One of the best sources of information on our climate is the Met Office which probably has everything you need to know. https://www.metoffice.gov.uk/weather/climate-change/what-is-climate-change
The BBC have produced a really simple guide to the climate emergency and, including a 3 minute video (which needs updating because the COP26 world summit on the climate has been postponed to 2021.)