Global average surface temperatures compared since 900 CE or why Global Warming is a hoax

Today, I put Google Search AI to this test on the Global Warming hoax and Climate Change religion!

Since the last ice age ended only in 1850, a warming of the Earth is to be expected.

If you subtract the urban heat island effect of an estimated 1-3 degrees Celsius than the post last ice age global average surface temperatures of 13.8 degrees Celsius are well below the Medieval Warm Period average of +14 degrees Celsius!

P.S. 

1. Why is the critically important urban heat island effect due to now 8 billion human beings so little researched or even neglected! Just a conspiracy theory or climate change is the greatest scam and scandal of our time.
2. Historic and current measurements of global average surface temperatures are generally dubious

Medieval Warm Period (900-1300 CE): +14 degrees Celsius

Little Ice Age (1450-1850 CE) -0.03 degrees Celsius

Post ice age 1850-today +13.8 degrees Celsius

Global urban heat island effect +1-3 degrees Celsius