Climate change

# Import modules
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import seaborn as sns

# Read the data
data = pd.read_csv("climate_change.csv", parse_dates=["date"])
data.head()

# Quick look at numeric variables
data.describe()

# Check for NaN
data.isnull().sum()

# Look at NaN
data[data.co2.isnull()]

# Drop NaN
data.dropna(inplace=True)
data.isnull().sum()

# Parameters for visualization with Seaborn
sns.set(rc={"figure.figsize":(15, 7)})
sns.set_context("notebook")
sns.set_style("whitegrid")

# Plot Co2 over time
sns.lineplot(x="date", y="co2", data=data)

# Plot relative_temp over time
sns.lineplot(x="date", y="relative_temp", data=data, color="darkred")

# Overlap the two plots
sns.lineplot(x="date", y="co2", data=data)
ax = plt.twinx()
sns.lineplot(x="date", y="relative_temp", data=data, color="darkred", ax=ax)
plt.grid(b=None)

# Create a new column, decade
data["decade"] = (np.floor(data.date.dt.year / 10) * 10).astype(int)

# Group by decade and compute the mean for co2 and relative_temp
grouped = data.groupby("decade", as_index=False)[["relative_temp", "co2"]].mean()

# Plot the results
ax = sns.barplot(x="decade", y="relative_temp", data=grouped, color="darkred")
ax1 = ax.twinx()
ax1.plot(grouped.co2, marker="o")
ax1.set_ylabel("Co2")
plt.legend(["Co2"], loc='upper left')
plt.grid(b=None)

# Plot relative_temp over co2
sns.scatterplot(x="co2", y="relative_temp", data=data, hue="relative_temp", palette="icefire", legend = False)

# Create a new column, after_70s
data["after_70s"] = ["Yes" if x > 1970 else "No" for x in data.decade]

# Calculate the mean co2 until 1980 (from 1950 to 1979) and after '70s
mean_co2_until_80 = data.query('after_70s == "No"').co2.mean()
mean_co2_after_70s = data.query('after_70s == "Yes"').co2.mean()

# Plot relative_temp over co2 with hue = after_70s
sns.scatterplot(x="co2", y="relative_temp", data=data, hue="after_70s", palette=["green", "darkred"])

# Draw a vertical line for mean co2 until '80s
plt.axvline(mean_co2_until_80, 0,data.relative_temp.max(),color="black",alpha=0.70)
plt.text(mean_co2_until_80,1,'Mean Co2 before 1980')

# Draw a vertical line for mean co2 after '70s
plt.axvline(mean_co2_after_70s, 0,data.relative_temp.max(),color="black", alpha=0.70)
plt.text(mean_co2_after_70s,1,'Mean Co2 from 1980')